High-thermal-conductivity and high-strength pouring sealant based on heat-resistant epoxy resin

Abstract

The invention discloses a high-thermal-conductivity and high-strength pouring sealant based on heat-resistant epoxy resin, which comprises the following components in parts by weight: 100 parts of imide modified epoxy resin with the epoxy value of 0.405-0.600 eq / 100g and the viscosity of 4000-30000 mPa.s at 25 DEG C; 10 to 100 parts of an amine curing agent; and 500 to 900 parts of surface modified heat conduction powder. According to the invention, the imide modified epoxy resin and various surface modified heat-conducting powder are combined, and the particle size distribution is optimized, so that the heat-conducting property, the mechanical strength, the heat resistance and the processability of the pouring sealant are remarkably improved, and the wide applicability of the pouring sealant in the high-tech fields of electronics, electrics, automobiles and the like is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of adhesives and potting glue, and in particular to a high-thermal-conductivity and high-strength potting glue based on heat-resistant epoxy resin. Background Art

[0002] With the development of science and technology and the continuous upgrading of industrial applications, the demand for thermal conductive materials in the fields of electronics, electrical and automobiles is growing. In potting products that require a combination of high thermal conductivity and heat resistance, traditional materials can no longer meet the requirements of modern applications. Epoxy resin is widely used in the potting field due to its good bonding properties, chemical resistance and excellent electrical insulation, especially in the protection and heat dissipation of electronic components such as motors, transformers and consumer electronics.

[0003] However, traditional thermally conductive epoxy resin potting glue faces several technical challenges during use. First, when a large amount of thermally conductive powder is filled to improve thermal conductivity, the mechanical properties of the potting glue are significantly reduced, resulting in a decrease in its compressive strength, impact resistance and durability in practical applications. This shortcoming is particularly evident in high stress and high temperature environments, which limits the application of potting glue. Secondly, the heat-resistant epoxy resins currently available on the market, such as phenolic epoxy resin, AG80, etc., usually have a high viscosity, which makes it difficult to evenly disperse the thermally conductive powder during the preparation process, limiting the large-scale filling of the thermally conductive powder, resulting in uneven thermal conductivity and reduced stability of the potting glue.

[0004] Based on this, there is an urgent need to develop a new type of modified epoxy resin material that can improve its mechanical strength and thermal conductivity while retaining its heat resistance. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the existing thermally conductive epoxy resin potting glue and broaden its application scope in high-end manufacturing industry, the present invention provides a high thermal conductivity and high strength potting glue based on heat-resistant epoxy resin.

[0006] The technical solution adopted by the present invention is as follows: a high thermal conductivity and high strength potting glue based on heat-resistant epoxy resin, comprising, by weight: 100 parts of an imide-modified epoxy resin with an epoxy value of 0.405-0.600eq / 100g and a viscosity of 4000-30000mPa.s at 25°C; 10-100 parts of an amine curing agent; and 500-900 parts of a surface-modified thermally conductive powder.

[0007] Preferably, the imide-modified epoxy resin is formulated in the following proportions by weight: 100 parts of epoxy resin; 5 to 20 parts of the imide bond-containing compound.

[0008] Preferably, the imide bond-containing compound includes one or more of N,N'-4,4'-diphenylmethane bismaleimide, maleimide, N-phenylmaleimide, phthalimide, and butyrimide.

[0009] Preferably, the preparation method of the imide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80-100° C. until they are completely dissolved into a transparent liquid; then the temperature is raised to 120-150° C., reacted for 2-4 hours, cooled, and the imide-modified epoxy resin is obtained.

[0010] Preferably, the amine curing agent includes one or more of diethylenetriamine, triethylenetetramine, diaminodiphenylmethane, isophoronediamine, polyetheramine, and polyamide.

[0011] Preferably, the surface-modified thermally conductive powder includes at least two of silicon dioxide modified by a silane coupling agent, aluminum oxide modified by a silane coupling agent, aluminum hydroxide modified by a titanate coupling agent, and boron nitride modified by an aluminate coupling agent.

[0012] Preferably, the surface-modified thermally conductive powder contains more than 30% of powder having a median particle size less than 5 μm.

[0013] Preferably, the surface-modified thermally conductive powder comprises, by weight: 150 to 350 parts of silicon dioxide modified with a silane coupling agent having a median particle size less than 5 μm; 50 to 90 parts of boron nitride modified with an aluminate coupling agent having a median particle size greater than 5 μm; and 250 to 540 parts of alumina modified with a silane coupling agent having a median particle size greater than 5 μm.

[0014] The second set of technical solutions adopted by the present invention is as follows: a method for preparing a high thermal conductivity and high strength potting glue based on a heat-resistant epoxy resin, the steps of which are as follows: uniformly mixing an imide-modified epoxy resin and a surface-modified thermally conductive powder according to a ratio, and dispersing them at a high speed of 500-3000 r / min; subsequently stirring them for 0.5-2 hours at a temperature of 80-100°C and a vacuum degree of 0.07-0.13MPa; after cooling to room temperature, mixing them with an amine curing agent according to a ratio, and then using them as a potting glue.

[0015] The present invention has the following beneficial effects: 1. Improve thermal conductivity: The imide-modified epoxy resin has a lower viscosity than the traditional multifunctional epoxy resin, which can be filled with a large amount of surface-modified thermal conductive powder and promote the uniform dispersion of the thermal conductive powder, significantly improving the thermal conductivity of the material; The combination of multiple thermally conductive powders and optimized particle size distribution helps to create a denser filling structure in the resin, providing a larger specific surface area, promoting the formation of heat conduction paths, and enhancing thermal management capabilities in high temperature environments, forming a stable thermal conduction network, and enhancing the overall thermal stability and thermal conductivity rate; 2. Improve mechanical properties: The interaction between the molecular chains of imide-modified epoxy resin is weakened, allowing the molecular chains to move with greater freedom. This flexibility can effectively enhance the plastic deformation ability of the material when subjected to stress, reduce stress concentration, and thus improve the compressive, impact and bending strengths. During the reaction with amine curing agents, the imide bond can further promote the cross-linking reaction, provide a stronger three-dimensional network structure, and enhance the mechanical strength of the material; By combining a variety of thermally conductive powders and optimizing the particle size distribution, more contact surfaces can be provided to form an effective interface with the epoxy resin, improving the density and uniformity of the material, enhancing the overall structural stability of the material, while also reducing the porosity and effectively reducing the strength loss caused by defects; 3. Enhance heat resistance: In high temperature environment, the imide bond can maintain its chemical structure without being destroyed, thus enhancing the heat resistance of epoxy resin, thereby improving the performance of potting compound in high temperature environment, reducing the performance degradation caused by temperature fluctuations, and ensuring the long-term stability of potting compound in high temperature working environment such as motors and transformers; 4. Optimize processing performance: The use of lower viscosity imide-modified epoxy resin makes it easier to evenly disperse the thermal conductive powder during the preparation process, avoiding the common filling difficulties and unevenness of traditional high-viscosity materials, improving production efficiency and ensuring the performance consistency of the final product, and facilitating the realization of efficient industrial production. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the embodiments.

[0017] Example 1 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0018] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0019] Amine curing agent, using isophorone diamine.

[0020] The surface-modified thermally conductive powder comprises, by weight: 500 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0021] Example 2 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0022] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0023] Amine curing agent, using isophorone diamine.

[0024] The surface modified thermal conductive powder comprises, by weight: 150 parts of alumina modified by a silane coupling agent with a median particle size less than 5 μm; and 350 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0025] Example 3 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0026] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0027] Amine curing agent, using isophorone diamine.

[0028] The surface modified thermal conductive powder comprises, by weight: 200 parts of alumina modified by a silane coupling agent with a median particle size less than 5 μm; and 300 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0029] Example 4 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0030] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0031] Amine curing agent, using isophorone diamine.

[0032] The surface-modified thermally conductive powder comprises, by weight: 700 parts of alumina modified by a silane coupling agent and having a median particle size greater than 5 μm.

[0033] Example 5 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0034] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0035] Amine curing agent, using isophorone diamine.

[0036] The surface modified thermal conductive powder comprises, by weight: 210 parts of alumina modified by a silane coupling agent with a median particle size less than 5 μm; and 490 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0037] Example 6 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0038] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0039] Amine curing agent, using isophorone diamine.

[0040] The surface modified thermal conductive powder comprises, by weight: 300 parts of alumina modified by a silane coupling agent with a median particle size less than 5 μm; and 400 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0041] Example 7 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0042] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0043] Amine curing agent, using isophorone diamine.

[0044] The surface-modified thermally conductive powder comprises, by weight: 900 parts of alumina modified by a silane coupling agent and having a median particle size greater than 5 μm.

[0045] Example 8 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0046] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0047] Amine curing agent, using isophorone diamine.

[0048] The surface modified thermal conductive powder comprises, by weight: 270 parts of alumina modified by a silane coupling agent with a median particle size less than 5 μm; and 630 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0049] Example 9 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0050] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0051] Amine curing agent, using isophorone diamine.

[0052] The surface modified thermal conductive powder comprises, by weight: 350 parts of alumina modified by a silane coupling agent with a median particle size less than 5 μm; and 550 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0053] Example 10 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0054] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0055] Amine curing agent, using isophorone diamine.

[0056] The surface modified thermal conductive powder comprises, by weight: 50 parts of boron nitride modified by an aluminate coupling agent with a median particle size greater than 5 μm; and 450 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0057] Embodiment 11 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0058] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0059] Amine curing agent, using isophorone diamine.

[0060] The surface modified thermal conductive powder comprises, by weight: 150 parts of silicon dioxide modified by a silane coupling agent with a median particle size of less than 5 μm; 50 parts of boron nitride modified by an aluminate coupling agent with a median particle size of greater than 5 μm; and 300 parts of alumina modified by a silane coupling agent with a median particle size of greater than 5 μm.

[0061] Example 12 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0062] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0063] Amine curing agent, using isophorone diamine.

[0064] The surface modified thermal conductive powder comprises, by weight: 200 parts of silicon dioxide modified by a silane coupling agent with a median particle size of less than 5 μm; 50 parts of boron nitride modified by an aluminate coupling agent with a median particle size of greater than 5 μm; and 250 parts of alumina modified by a silane coupling agent with a median particle size of greater than 5 μm.

[0065] Example 13 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0066] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0067] Amine curing agent, using isophorone diamine.

[0068] The surface modified thermal conductive powder comprises, by weight: 70 parts of boron nitride modified by an aluminate coupling agent with a median particle size greater than 5 μm; and 630 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0069] Embodiment 14 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0070] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0071] Amine curing agent, using isophorone diamine.

[0072] The surface modified thermal conductive powder comprises, by weight: 210 parts of silicon dioxide modified by a silane coupling agent with a median particle size less than 5 μm; 70 parts of boron nitride modified by an aluminate coupling agent with a median particle size greater than 5 μm; and 420 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0073] Embodiment 15 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0074] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0075] Amine curing agent, using isophorone diamine.

[0076] The surface modified thermal conductive powder comprises, by weight: 300 parts of silicon dioxide modified by a silane coupling agent with a median particle size less than 5 μm; 70 parts of boron nitride modified by an aluminate coupling agent with a median particle size greater than 5 μm; and 330 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0077] Example 16 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0078] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0079] Amine curing agent, using isophorone diamine.

[0080] The surface modified thermal conductive powder comprises, by weight: 90 parts of boron nitride modified by an aluminate coupling agent with a median particle size greater than 5 μm; and 810 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0081] Embodiment 17 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0082] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0083] Amine curing agent, using isophorone diamine.

[0084] The surface modified thermal conductive powder comprises, by weight: 270 parts of silicon dioxide modified by a silane coupling agent with a median particle size of less than 5 μm; 90 parts of boron nitride modified by an aluminate coupling agent with a median particle size of greater than 5 μm; and 540 parts of alumina modified by a silane coupling agent with a median particle size of greater than 5 μm.

[0085] Embodiment 18 A high-thermal-conductivity and high-strength potting compound based on heat-resistant epoxy resin includes, by weight: 100 parts of imide-modified epoxy resin; 20 parts of amine curing agent; 500 parts of surface-modified thermally conductive powder. The specific preparation method is: uniformly mix the imide-modified epoxy resin and the surface-modified thermally conductive powder according to the ratio, and disperse them at a high speed of 2000r / min; then stir for 2 hours at a temperature of 100°C and a vacuum degree of 0.10MPa; after cooling to room temperature, mix with the amine curing agent according to the ratio, and then use it as a potting compound.

[0086] The amide-modified epoxy resin includes, by weight: 100 parts of epoxy resin; 5 parts of an imide-bond-containing compound. The epoxy resin is epoxy resin E51, and the imide-bond-containing compound is N,N'-4,4'-diphenylmethane bismaleimide. The preparation method of the amide-modified epoxy resin is: uniformly mix the epoxy resin and the imide-bond-containing compound according to a ratio; stir at a temperature of 80°C until completely dissolved into a transparent liquid; then raise the temperature to 140°C, react for 4 hours, cool down, and discharge the material to obtain the imide-modified epoxy resin.

[0087] Amine curing agent, using isophorone diamine.

[0088] The surface modified thermal conductive powder comprises, by weight: 350 parts of silicon dioxide modified by a silane coupling agent with a median particle size of less than 5 μm; 90 parts of boron nitride modified by an aluminate coupling agent with a median particle size of greater than 5 μm; and 460 parts of alumina modified by a silane coupling agent with a median particle size of greater than 5 μm.

[0089] Control group 1 A potting adhesive based on bisphenol A epoxy resin comprises, by weight: 100 parts of bisphenol A epoxy resin; 20 parts of amine curing agent; and 900 parts of surface-modified thermally conductive powder.

[0090] Amine curing agent, using isophorone diamine.

[0091] The surface-modified thermally conductive powder comprises, by weight: 900 parts of alumina modified by a silane coupling agent and having a median particle size greater than 5 μm.

[0092] Control group 2 A potting adhesive based on bisphenol A epoxy resin comprises, by weight: 100 parts of bisphenol A epoxy resin; 20 parts of amine curing agent; and 900 parts of surface-modified thermally conductive powder.

[0093] Amine curing agent, using isophorone diamine.

[0094] The surface modified thermal conductive powder comprises, by weight: 270 parts of alumina modified by a silane coupling agent with a median particle size less than 5 μm; and 630 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0095] Control group 3 A potting adhesive based on tetraglycidylamine epoxy resin comprises, by weight: 100 parts of bisphenol A epoxy resin; 32 parts of amine curing agent; and 500 parts of surface-modified thermally conductive powder.

[0096] Amine curing agent, using isophorone diamine.

[0097] The surface-modified thermally conductive powder comprises, by weight: 500 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0098] Control group 4 A potting adhesive based on tetraglycidylamine epoxy resin comprises, by weight: 100 parts of bisphenol A epoxy resin; 32 parts of amine curing agent; and 500 parts of surface-modified thermally conductive powder.

[0099] Amine curing agent, using isophorone diamine.

[0100] The surface modified thermal conductive powder comprises, by weight: 150 parts of alumina modified by a silane coupling agent with a median particle size less than 5 μm; and 350 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0101] Control group 5 A potting adhesive based on bisphenol A epoxy resin comprises, by weight: 100 parts of bisphenol A epoxy resin; 20 parts of amine curing agent; and 900 parts of surface-modified thermally conductive powder.

[0102] Amine curing agent, using isophorone diamine.

[0103] The surface modified thermal conductive powder comprises, by weight: 90 parts of boron nitride modified by an aluminate coupling agent with a median particle size greater than 5 μm; and 810 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0104] Control group 6 A potting adhesive based on bisphenol A epoxy resin comprises, by weight: 100 parts of bisphenol A epoxy resin; 20 parts of amine curing agent; and 900 parts of surface-modified thermally conductive powder.

[0105] Amine curing agent, using isophorone diamine.

[0106] The surface modified thermal conductive powder comprises, by weight: 270 parts of silicon dioxide modified by a silane coupling agent with a median particle size of less than 5 μm; 90 parts of boron nitride modified by an aluminate coupling agent with a median particle size of greater than 5 μm; and 540 parts of alumina modified by a silane coupling agent with a median particle size of greater than 5 μm.

[0107] Control group 7 A potting adhesive based on tetraglycidylamine epoxy resin comprises, by weight: 100 parts of bisphenol A epoxy resin; 32 parts of amine curing agent; and 500 parts of surface-modified thermally conductive powder.

[0108] Amine curing agent, using isophorone diamine.

[0109] The surface modified thermal conductive powder comprises, by weight: 50 parts of boron nitride modified by an aluminate coupling agent with a median particle size greater than 5 μm; and 450 parts of alumina modified by a silane coupling agent with a median particle size greater than 5 μm.

[0110] Control group 8 A potting adhesive based on tetraglycidylamine epoxy resin comprises, by weight: 100 parts of bisphenol A epoxy resin; 32 parts of amine curing agent; and 500 parts of surface-modified thermally conductive powder.

[0111] Amine curing agent, using isophorone diamine.

[0112] The surface modified thermal conductive powder comprises, by weight: 150 parts of silicon dioxide modified by a silane coupling agent with a median particle size of less than 5 μm; 50 parts of boron nitride modified by an aluminate coupling agent with a median particle size of greater than 5 μm; and 300 parts of alumina modified by a silane coupling agent with a median particle size of greater than 5 μm.

[0113] The performance test results of each embodiment and the control group are shown in the following table:

[0114] After analyzing the test results in the above table, the following conclusions are drawn.

[0115] (1) Examples 7 to 9 and Examples 16 to 18 achieve better thermal conductivity, which is attributed to the fact that filling a large amount of thermally conductive powder can effectively improve the thermal conductivity of the potting compound.

[0116] Heat-resistant modified epoxy resin has a lower viscosity than multifunctional epoxy resin. Its low viscosity allows it to be filled with a large amount of thermally conductive powder, making the product more convenient in preparation and process operation, while helping to improve the uniformity and thermal conductivity of the product. In addition, the introduction of the imide structure improves the compatibility of the epoxy resin, making it easier to mix evenly with various thermally conductive powders, ensuring that the thermally conductive powder can fully exert its thermal conductivity in the resin matrix, which helps to improve the overall thermal conductivity.

[0117] (2) Example 18 has the best tensile strength, which is attributed to the use of heat-resistant modified epoxy resin, a combination of multiple thermal conductive powders and the optimization of their particle size distribution.

[0118] The imide bond is a functional group with high thermal stability. Introducing it into the molecular structure of epoxy resin can significantly improve the heat resistance of the material. At high temperatures, the imide bond can maintain its chemical structure without being destroyed, thereby improving the performance of the potting compound in high temperature environments and reducing performance degradation caused by temperature changes. Compared with traditional epoxy resins, after adding imide, the interaction between molecular chains is weakened, allowing the molecular chains to move with greater freedom. This flexibility can effectively enhance the plastic deformation ability of the material when subjected to force, reduce stress concentration, and thus improve compression, impact and bending strength. In addition, during the reaction with amine curing agents, the introduction of imide bonds can further promote the cross-linking reaction, which means a more solid three-dimensional network structure, which has a significant effect on improving the mechanical strength and temperature resistance of the material.

[0119] Smaller silica particles help create a denser filling structure in the potting compound, provide a larger specific surface area, promote the formation of heat conduction paths, and thus improve the overall thermal conductivity. Boron nitride, as a high thermal conductivity material, can directly enhance the thermal management capabilities of the potting compound in high temperature environments, and significantly improve the overall thermal efficiency, especially under high temperature conditions, enhancing the thermal stability and thermal conductivity rate of the material. Alumina particles provide good strength and structural support, enhance the toughness of the overall material, and form a stable thermal network together with silica and boron nitride.

[0120] In terms of dosage, 350 parts of silica modified with a silane coupling agent with a median particle size less than 5μm, 90 parts of boron nitride modified with an aluminate coupling agent with a median particle size greater than 5μm, and 460 parts of alumina modified with a silane coupling agent with a median particle size greater than 5μm form a good proportion. The complementary particle sizes and material properties enable the combined material to achieve an optimal balance in thermal conductivity, mechanical properties and processing properties, meeting the requirements of high thermal conductivity, high strength and good processability.

[0121] (3) Example 12 has the best flexural strength, which is attributed to the silane coupling agent-modified silica having a larger proportion of a median particle size of less than 5 μm among the various thermally conductive powder combinations used.

[0122] Silica has a large specific surface area due to its particle size of less than 5μm, which can provide more contact surfaces to form an effective interface with epoxy resin. The stronger interface bonding force promotes the load transfer inside the material, reduces the stress concentration phenomenon, and thus improves the overall bending strength. The fine particles of silica can effectively fill the tiny gaps in the epoxy resin matrix, improve the density and uniformity of the material, enhance the overall structural stability of the material, and also reduce the porosity, effectively reducing the strength loss caused by defects. In addition, the presence of silica forms a flexible support effect on the structure of the epoxy resin, so that when subjected to external forces, the material can produce a certain plastic deformation. This deformation can better disperse the applied stress instead of directly causing rupture, so that the material can maintain a higher bending strength under high stress.

[0123] The composite use of silicon dioxide, boron nitride and aluminum oxide complements the characteristics of each material. Aluminum nitride and aluminum oxide provide additional heat resistance and structural strength, while fine silicon dioxide can evenly disperse heat and mechanical stress under high temperature or mechanical loading conditions, reduce local overheating and high stress concentration, and effectively improve the durability and bending strength of the material.

[0124] Obviously, the above embodiments of the present invention are only examples for explaining the present invention, and are not intended to limit the implementation methods of the present invention. Other obvious changes or modifications derived from the essence of the present invention still fall within the protection scope of the present invention.

Claims

1. A high thermal conductivity and high strength potting glue based on heat-resistant epoxy resin, characterized in that: In parts by weight, it comprises: 100 parts of an imide-modified epoxy resin having an epoxy value of 0.405-0.600 eq / 100 g and a viscosity of 4000-30000 mPa.s at 25°C; Amine curing agent, 10-100 parts; Surface modified thermal conductive powder, 500~900 parts.

2. The high thermal conductivity and high strength potting adhesive based on heat-resistant epoxy resin according to claim 1, characterized in that: The imide-modified epoxy resin is formulated in the following proportions by weight: Epoxy resin, 100 parts; Compounds containing imide bonds, 5 to 20 parts.

3. The high thermal conductivity and high strength potting adhesive based on heat-resistant epoxy resin according to claim 2, characterized in that: The imide bond-containing compound includes one or more of N,N'-4,4'-diphenylmethane bismaleimide, maleimide, N-phenylmaleimide, phthalimide, and butyrimide.

4. The high thermal conductivity and high strength potting adhesive based on heat-resistant epoxy resin according to claim 2 or 3, characterized in that: The preparation method of the imide-modified epoxy resin is as follows: epoxy resin and an imide-bond-containing compound are uniformly mixed according to a ratio; at a temperature of 80-100° C., stirred until completely dissolved into a transparent liquid; then the temperature is raised to 120-150° C., reacted for 2-4 hours, cooled, and the imide-modified epoxy resin is obtained by discharging.

5. The high thermal conductivity and high strength potting adhesive based on heat-resistant epoxy resin according to claim 1, characterized in that: The amine curing agent includes one or more of diethylenetriamine, triethylenetetramine, diaminodiphenylmethane, isophoronediamine, polyetheramine, and polyamide.

6. The high thermal conductivity and high strength potting adhesive based on heat-resistant epoxy resin according to claim 1, characterized in that: The surface-modified thermally conductive powder comprises at least two of silicon dioxide modified by a silane coupling agent, aluminum oxide modified by a silane coupling agent, aluminum hydroxide modified by a titanate coupling agent, and boron nitride modified by an aluminate coupling agent.

7. The high thermal conductivity and high strength potting adhesive based on heat-resistant epoxy resin according to claim 1, characterized in that: The surface modified thermally conductive powder contains more than 30% of powder with a median particle size less than 5 μm.

8. The high thermal conductivity and high strength potting adhesive based on heat-resistant epoxy resin according to claim 1, 6 or 7, characterized in that: The surface modified thermal conductive powder comprises, by weight: 150-350 parts of silicon dioxide modified by a silane coupling agent with a median particle size less than 5 μm; 50-90 parts of boron nitride modified by an aluminate coupling agent with a median particle size greater than 5 μm; and 250-540 parts of aluminum oxide modified by a silane coupling agent with a median particle size greater than 5 μm.

9. A method for preparing a high thermal conductivity and high strength potting adhesive based on a heat-resistant epoxy resin according to any one of claims 1 to 8, characterized in that: The steps are as follows: uniformly mix the imide-modified epoxy resin and the surface-modified thermal conductive powder according to the ratio, and disperse them at a high speed of 500-3000 r / min; then stir them for 0.5-2 hours at a temperature of 80-100°C and a vacuum degree of 0.07-0.13 MPa; after cooling to room temperature, mix them with an amine curing agent according to the ratio and use them as a potting glue.

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