A high thermal conductivity insulating resin and preparation method thereof

Abstract

The present invention belongs to the technical field of thermally conductive insulating materials, specifically relating to a highly thermally conductive insulating resin and its preparation method. The insulating resin comprises the following raw materials by weight: 30-50 parts of epoxy resin; 40-60 parts of organically modified boron nitride; and 20-30 parts of an anhydride curing agent. The preparation method comprises: uniformly mixing the epoxy resin, organically modified boron nitride, and anhydride curing agent in a weight ratio, performing a first curing step after hot pressing, then heating the resin for a second curing step, and cooling the resin to obtain the insulating resin. The insulating resin material prepared by the present invention has excellent flame retardancy, mechanical properties, and high thermal conductivity and insulation properties, and has great market application value in the fields of electronics, electrical appliances, and power supply.

Description

Technical Field

[0001] The invention belongs to the technical field of thermally conductive insulating materials, and particularly relates to a high thermally conductive insulating resin and a preparation method thereof. Background Art

[0002] The rapid development of high-density microelectronics assembly and integration technologies is placing increasing demands on the thermal conductivity of materials. As electronic devices and logic circuits shrink exponentially, the amount of heat generated during operation increases dramatically. This excessive heat generation leads to heat accumulation, and long-term high-temperature operation significantly reduces the lifespan of devices. To extend device lifespan, it is necessary to improve the device's heat dissipation capabilities and keep its operating temperature within a normal range. Therefore, the research and preparation of materials with high thermal conductivity are necessary to address the problem of excessive heat accumulation.

[0003] Among them, epoxy resin has the characteristics of good processing technology, high adhesion, excellent dielectric properties, small shrinkage, and good stability. It is widely used in the fields of electronics and electrical appliances. However, epoxy resin itself has low thermal conductivity and poor thermal conductivity, and its thermal conductivity needs to be improved in the application of electronic and electrical equipment. Usually, high thermal conductivity fillers are added to epoxy resin to improve its thermal conductivity; the patent with application number 201910175537.4 discloses an epoxy resin thermal conductive insulation material and its preparation method. The material includes an epoxy resin base material, an inorganic filler and a curing agent. The inorganic filler is composed of three fillers with different particle sizes; the thermal conductivity of the prepared material at 30°C can reach 1.25W / mK, and the maximum can reach 1.62W / mK. The resistivity of the material at 30°C is 2.9×10 16 Ω·cm or more, meeting the application requirements of high-insulation scenarios such as power electronic transformers and saturated reactors. Patent application number 202210586893.7 provides a high-thermal-conductivity resin insulation material and its preparation method. The material comprises the following raw materials by weight: 30-40 parts epoxy resin, 30-40 parts epoxy resin curing agent, 20-30 parts epoxy resin diluent, 2-3 parts epoxy resin accelerator, and a boron nitride-POSS skeleton. The addition of the boron nitride-POSS skeleton improves the thermal conductivity of the material. The resulting material has a 3D skeleton structure and excellent mechanical properties.

[0004] However, none of the above materials involve improvements in properties such as flame retardancy, and the thermal conductivity achieved cannot meet the thermal conductivity requirements of high-insulation and ultra-high voltage electrical equipment. Summary of the Invention

[0005] The purpose of the present invention is to address the deficiencies of the prior art and provide a high thermal conductivity insulating resin and a preparation method thereof. The preparation process of the insulating resin is simple and easy to produce. It also has good flame retardant properties, mechanical properties and high thermal conductivity and insulation properties, and has great market application value in the fields of electronics, electrical appliances and power supply.

[0006] The technical solutions adopted by the present invention to achieve the above-mentioned purpose are:

[0007] A high thermal conductivity insulating resin, the insulating resin comprises the following raw materials in parts by weight: 30-50 parts of epoxy resin; 40-60 parts of organic modified boron nitride; 20-30 parts of anhydride curing agent;

[0008] Furthermore, the epoxy resin is one or a mixture of bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, and novolac epoxy resin; preferably, the epoxy resin is bisphenol A epoxy resin; the anhydride curing agent is one or a mixture of phthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and pyromellitic anhydride; preferably, the anhydride curing agent is phthalic anhydride.

[0009] Furthermore, the preparation method of the organically modified boron nitride is:

[0010] S1. Dispersing boron nitride in a sodium hydroxide aqueous solution, then adding the solution to a hydrothermal reactor, reacting at 120-130° C. for 20-24 hours, and naturally cooling to room temperature after the reaction is complete. Collecting the precipitate after centrifugation, washing it with deionized water until it is neutral, and drying it to obtain hydroxylated boron nitride;

[0011] S2. Add hydroxylated boron nitride to the toluene solution, stir for 20-30 minutes, then dropwise add 3-aminopropyltriethoxysilane, and under nitrogen protection, heat to 110-120°C, reflux for 10-12 hours. After the reaction is completed, naturally cool to room temperature, collect the precipitate after centrifugation, wash with toluene and ethanol in sequence, and dry to obtain amino boron nitride;

[0012] S3, adding the amino boron nitride to the acetonitrile solution, adding potassium iodide and potassium carbonate under nitrogen protection, and then adding benzyl chloride dropwise, heating to 50-60 ° C, reacting for 3-4 hours, and after the reaction is completed, naturally cooling to room temperature, filtering, and washing the filter residue with water and dichloromethane in turn, and drying to obtain modified amino boron nitride;

[0013] S4. Disperse the modified amino boron nitride in an aqueous solution of aminotrimethylenephosphonic acid, heat to 60-70°C, react for 2-3 hours, and after the reaction is completed, naturally cool to room temperature, filter, and wash the filter residue with ethanol and deionized water in turn until it is neutral, and dry to obtain organically modified boron nitride.

[0014] Furthermore, in step S1, the mass ratio of boron nitride to sodium hydroxide is 1:20-25; the concentration of the sodium hydroxide aqueous solution is 4-5 mol / mL; in step S2, the mass ratio of hydroxylated boron nitride to 3-aminopropyltriethoxysilane is 1:0.3-0.5; and the amount of the toluene solution used is 25-30 times the mass of the hydroxylated boron nitride.

[0015] Furthermore, the mass ratio of the amination boron nitride, benzyl chloride, potassium carbonate, and potassium iodide in step S3 is 1:0.8-1.0:1.3-1.5:0.6-0.8; the amount of the acetonitrile solution is 25-30 times the mass of the amination boron nitride; the mass ratio of the modified amination boron nitride nanometer and aminotrimethylene phosphonic acid in step S4 is 1:0.6-0.8; the concentration of the aminotrimethylene phosphonic acid aqueous solution is 0.1-0.15 mol / L.

[0016] The present invention provides a preparation method of a high thermal conductive insulating resin, comprising the following steps: uniformly mixing epoxy resin, organic modified boron nitride, and an acid anhydride curing agent according to a weight ratio, performing a first curing after hot pressing, then heating and performing a second curing, and obtaining the insulating resin after cooling.

[0017] Furthermore, the temperature of the first curing is 80-100°C, and the time is 9-10 hours; preferably, the temperature of the first curing is 90°C, and the time is 9 hours; the temperature of the second curing is 120-140°C, and the time is 5-6 hours; preferably, the temperature of the second curing is 140°C, and the time is 5 hours.

[0018] The present invention has the following beneficial effects:

[0019] The present invention modifies inorganic filler boron nitride. First, the surface of the boron nitride is hydroxylated to introduce hydroxyl groups, and then reacted with 3-aminopropyltriethoxysilane to obtain amino-boron nitride. Then, the boron nitride is reacted with benzyl chloride and aminotrimethylenephosphonic acid in sequence to obtain organically modified boron nitride. The introduction of the rigid benzene ring group can improve the mechanical properties of the resin material. The introduction of the aminotrimethylenephosphonic acid, on the one hand, enriches the surface of the organically modified boron nitride with phosphorus-hydroxyl groups, which can form more hydrogen bonds with the active hydroxyl groups in the epoxy resin structure, thereby making the organically modified boron nitride and the epoxy resin more tightly bonded. On the other hand, the organically modified boron nitride can be decomposed at high temperature to form PO, P=O and nitride, which capture free radicals generated by the decomposition of the resin material and generate a gas barrier layer, thereby inhibiting the formation and propagation of flames. A carbon layer is also formed on the surface of the resin material. The presence of the boron nitride helps to increase the density of the carbon layer. At the same time, the silicon-oxygen structure in the organically modified boron nitride also generates a silicon-carbon barrier layer during combustion, preventing the resin material from contacting with oxygen, thereby synergistically generating a flame retardant effect, thereby greatly improving the flame retardant properties of the resin material.

[0020] The present invention provides a method for preparing a high-thermal-conductivity insulating resin, which has a simple preparation process and is easy to produce. Under the action of an acid anhydride curing agent, a staged curing method of first low-temperature curing and then high-temperature curing is adopted, which can prevent the resin cured product from generating bubbles and uneven cross-linking due to excessively high temperatures at the beginning of curing, thereby affecting the performance of the resin. The insulating resin material prepared by the present invention has good flame retardant properties, mechanical properties and high thermal conductivity and insulation properties, and has great market application value in the fields of electronics, electrical appliances and power supply. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] Boron nitride (CAS number 10043-11-5) was purchased from Shanghai Xiaohuang Nano Technology Co., Ltd.; phthalic anhydride (CAS number 85-44-9); hexahydrophthalic anhydride (CAS number 13149-00-3); sodium hydroxide (CAS number 1310-73-2); 3-aminopropyltriethoxysilane (CAS number 919-30-2); potassium iodide (CAS number 7681-11-0); potassium carbonate (CAS number 584-08-7); benzyl chloride (CAS number 100-44-7); aminotrimethylenephosphonic acid (CAS number 6419-19-8); toluene (CAS number 108-88-3); acetonitrile (CAS number 75-05-8); ethanol (CAS number 64-17-5); and dichloromethane (CAS number 75-09-2). All chemical reagents were commercially available.

[0023] Example 1

[0024] A high thermal conductive insulating resin comprises the following raw materials in parts by weight: 50 parts of epoxy resin; 60 parts of organically modified boron nitride; and 30 parts of an acid anhydride curing agent. The epoxy resin is bisphenol A epoxy resin, and the acid anhydride curing agent is phthalic anhydride.

[0025] The preparation method of organically modified boron nitride is:

[0026] S1. Disperse 20 parts by weight of boron nitride in a 5 mol / mL aqueous sodium hydroxide solution (containing 400 parts by weight of sodium hydroxide), then add the mixture to a hydrothermal reactor, react at 130° C. for 20 h, and after completion of the reaction, naturally cool to room temperature. Collect the precipitate after centrifugation, wash it with deionized water until it is neutral, and dry it to obtain hydroxylated boron nitride;

[0027] S2. Add 10 parts by weight of hydroxylated boron nitride to 250 parts by weight of toluene solution, stir for 30 minutes, then dropwise add 5 parts by weight of 3-aminopropyltriethoxysilane, and heat to 120°C under nitrogen protection, reflux for 10 hours. After the reaction is completed, naturally cool to room temperature, collect the precipitate after centrifugation, and wash it with toluene and ethanol in turn, and dry it to obtain amino boron nitride; in this reaction step, the hydroxyl groups on the surface of the hydroxylated boron nitride react with 3-aminopropyltriethoxysilane to form a silicon-oxygen chemical bond, thereby introducing the amino group into the surface of the hydroxylated boron nitride.

[0028] S3, 10 parts by weight of aminated boron nitride are added to 250 parts by weight of acetonitrile solution, and under nitrogen protection, 8 parts by weight of potassium iodide and 15 parts by weight of potassium carbonate are added, and then 10 parts by weight of benzyl chloride are added dropwise, and the temperature is raised to 60 ° C. and the reaction is reacted for 4 hours. After the reaction is completed, it is naturally cooled to room temperature and filtered. The filter residue is washed with water and dichloromethane in turn, and dried to obtain modified aminated boron nitride; in this step reaction, the amino group on the surface of the aminated boron nitride reacts with the benzyl chloride under the action of potassium carbonate and potassium iodide, and the benzyl ring is introduced into the surface of the aminated boron nitride through the formed imino group.

[0029] S4. Disperse 10 parts by weight of modified amino-boron nitride in a 0.1 mol / mL aqueous solution of aminotrimethylene phosphonic acid (containing 8 parts by weight of aminotrimethylene phosphonic acid), heat to 70°C, react for 2 hours, and after the reaction is completed, naturally cool to room temperature, filter, and wash the filter residue with ethanol and deionized water in turn until neutral, and dry to obtain organically modified boron nitride; in this step of the reaction, the imino group contained on the surface of the modified amino-boron nitride reacts with aminotrimethylene phosphonic acid to form an ionic bond, thereby achieving the adsorption of aminotrimethylene phosphonic acid on the surface of the modified amino-boron nitride.

[0030] A method for preparing a high-thermal-conductivity insulating resin comprises the following steps: uniformly mixing epoxy resin, organically modified boron nitride, and an acid anhydride curing agent according to a weight ratio, performing a first curing after hot pressing, then heating for a second curing, and cooling to obtain the insulating resin; wherein the first curing temperature is 90° C. and the time is 9 hours; and the second curing temperature is 140° C. and the time is 5 hours.

[0031] Example 2

[0032] A high thermal conductive insulating resin comprises the following raw materials in parts by weight: 30 parts of epoxy resin; 40 parts of organically modified boron nitride; and 20 parts of an acid anhydride curing agent. The epoxy resin is bisphenol F epoxy resin, and the acid anhydride curing agent is hexahydrophthalic anhydride.

[0033] The preparation method of organically modified boron nitride is the same as that in Example 1.

[0034] A method for preparing a high-thermal-conductivity insulating resin comprises the following steps: uniformly mixing epoxy resin, organically modified boron nitride, and an acid anhydride curing agent according to a weight ratio, performing a first curing after hot pressing, then heating for a second curing, and cooling to obtain the insulating resin; wherein the first curing temperature is 100° C. and the time is 9 hours; and the second curing temperature is 130° C. and the time is 6 hours.

[0035] Example 3

[0036] A high thermal conductive insulating resin comprises the following raw materials in parts by weight: 40 parts of epoxy resin; 50 parts of organically modified boron nitride; and 25 parts of an acid anhydride curing agent. The epoxy resin is bisphenol F epoxy resin, and the acid anhydride curing agent is phthalic anhydride.

[0037] The preparation method of organically modified boron nitride is the same as that in Example 1.

[0038] A method for preparing a high-thermal-conductivity insulating resin comprises the following steps: uniformly mixing epoxy resin, organically modified boron nitride, and an acid anhydride curing agent according to a weight ratio, performing a first curing after hot pressing, then heating for a second curing, and cooling to obtain the insulating resin; wherein the first curing temperature is 80° C. and the time is 10 hours; and the second curing temperature is 120° C. and the time is 6 hours.

[0039] Example 4

[0040] A high thermal conductive insulating resin comprises the following raw materials in parts by weight: 50 parts of epoxy resin; 40 parts of organically modified boron nitride; and 20 parts of an acid anhydride curing agent. The epoxy resin is bisphenol A epoxy resin, and the acid anhydride curing agent is hexahydrophthalic anhydride.

[0041] The preparation method of organically modified boron nitride is the same as that in Example 1.

[0042] A method for preparing a high-thermal-conductivity insulating resin comprises the following steps: uniformly mixing epoxy resin, organically modified boron nitride, and an acid anhydride curing agent according to a weight ratio, performing a first curing after hot pressing, then heating for a second curing, and cooling to obtain the insulating resin; wherein the first curing temperature is 100° C. and the time is 9 hours; and the second curing temperature is 130° C. and the time is 5 hours.

[0043] Comparative Example 1

[0044] Compared with Example 1, the raw material composition of the insulating resin and the curing method during processing are different.

[0045] A high thermal conductive insulating resin comprises the following raw materials in parts by weight: 50 parts of epoxy resin; 60 parts of organically modified boron nitride; and 30 parts of an aniline curing agent. The epoxy resin is bisphenol A epoxy resin, and the aniline curing agent is diethyltoluenediamine.

[0046] The preparation method of organically modified boron nitride is the same as that in Example 1.

[0047] A method for preparing a high-thermal-conductivity insulating resin comprises the following steps: uniformly mixing epoxy resin, organically modified boron nitride, and an aniline curing agent according to a weight ratio, hot-pressing and curing the mixture, and cooling the mixture to obtain the insulating resin; wherein the curing temperature is 140° C. and the curing time is 9 hours.

[0048] Comparative Example 2

[0049] Compared with Example 1, the raw material composition of the insulating resin is different.

[0050] A high thermal conductive insulating resin comprises the following raw materials in parts by weight: 50 parts of epoxy resin; 60 parts of modified amino boron nitride; and 30 parts of an acid anhydride curing agent. The epoxy resin is bisphenol A epoxy resin, and the acid anhydride curing agent is phthalic anhydride.

[0051] The preparation method of modified amino boron nitride is the same as that in Example 1.

[0052] A method for preparing a high-thermal-conductivity insulating resin comprises the following steps: uniformly mixing an epoxy resin, modified amino boron nitride, and an acid anhydride curing agent according to a weight ratio, performing a first curing after hot pressing, then heating for a second curing, and cooling to obtain the insulating resin; wherein the first curing temperature is 90° C. and the time is 9 hours; and the second curing temperature is 140° C. and the time is 5 hours.

[0053] Comparative Example 3

[0054] Compared with Example 1, the raw material composition of the insulating resin is different.

[0055] A high thermal conductive insulating resin comprises the following raw materials in parts by weight: 50 parts of epoxy resin; 60 parts of boron nitride; and 30 parts of an acid anhydride curing agent. The epoxy resin is bisphenol A epoxy resin, and the acid anhydride curing agent is phthalic anhydride.

[0056] A method for preparing a high-thermal-conductivity insulating resin comprises the following steps: uniformly mixing epoxy resin, boron nitride, and an acid anhydride curing agent according to a weight ratio, performing a first curing after hot pressing, then heating for a second curing, and cooling to obtain the insulating resin; wherein the first curing temperature is 90° C. and the time is 9 hours; and the second curing temperature is 140° C. and the time is 5 hours.

[0057] Related tests

[0058] 1. Mechanical, thermal conductivity and insulation performance testing of insulating resin

[0059] The samples of Examples 1-3 and Comparative Examples 1-3 were tested, wherein tensile tests were performed using an Instron electronic universal testing machine according to ASTM D638-10 standard; thermal conductivity tests in the thickness direction were performed using a DRL-III thermal conductivity tester according to ASTM D5470 standard; and volume resistivity tests were performed according to ASTM D257 standard. The test results are shown in Table 1.

[0060] Table 1 Test results of mechanical, thermal conductivity and insulation properties of insulating resin

[0061]

[0062]

[0063] As shown in Table 1, the tensile strength, flexural strength, thermal conductivity and volume resistivity of the insulating resins prepared in Examples 1-4 are all higher than those in Comparative Examples 1-3, indicating that the method for preparing a high thermal conductivity insulating resin provided by the present invention can successfully prepare a resin material with good mechanical properties and high thermal conductivity and insulation properties; compared with Comparative Example 1 (using an aniline curing agent and performing one-time curing during processing), in Example 1, low-temperature curing is first performed and then high-temperature curing is performed to prevent the resin from being cured at too high a temperature at the beginning of curing, thereby preventing bubbles from being generated in the resin cured product and uneven cross-linking, thereby affecting the performance of the resin; acid anhydride curing The agent can cross-link through the epoxy groups and hydroxyl groups in the epoxy resin structure to form a resin material with a tighter structure and better performance; compared with Comparative Example 2 (modified amino boron nitride) and Comparative Example 3 (boron nitride), the organic modified boron nitride added in Example 1 contains benzene ring groups and more phosphorus-hydroxyl groups on the surface, wherein the rigid benzene ring groups can improve the mechanical properties of the material, and the phosphorus-hydroxyl groups can form more hydrogen bonds with the active group hydroxyl groups in the epoxy resin structure, thereby making the combination between the organic modified boron nitride and the epoxy resin tighter, forming a resin material with better thermal conductivity and insulation properties.

[0064] 2. Flame retardant performance test of insulating resin

[0065] The samples of Examples 1-3 and Comparative Examples 1-3 were tested. The limiting oxygen index test standard was GB / T 2406-2009. The combustion level was tested using a vertical combustion tester. The test results are shown in Table 2.

[0066] Table 2 Flame retardant performance test results of insulating resin

[0067]

[0068]

[0069] As shown in Table 2, the UL-94 grade of the insulating resins prepared by Examples 1-4 is V-0, and the limiting oxygen index is higher than that of Comparative Examples 1-3, indicating that the method for preparing a high thermal conductive insulating resin provided by the present invention can successfully prepare a resin material with excellent flame retardant properties; compared with Comparative Example 1 (using an aniline curing agent and performing a single curing during processing), the use of a segmented curing under the action of an anhydride curing agent in Example 1 helps to form a resin material with better flame retardant properties; compared with Comparative Example 2 (modified amino boron nitride) and Comparative Example 3 (boron nitride), The surface of the organically modified boron nitride added in Example 1 contains aminotrimethylenephosphonic acid, which can decompose at high temperatures to form PO, P=O and nitride, capturing free radicals generated by the decomposition of the resin material and forming a gas barrier layer, thereby inhibiting the formation and spread of flames. In addition, a carbon layer is formed on the surface of the resin material. The presence of boron nitride helps to increase the density of the carbon layer. At the same time, the silicon-oxygen structure in the organically modified boron nitride also generates a silicon-carbon barrier layer during combustion, preventing the resin material from contacting oxygen, synergistically producing a flame retardant effect, thereby greatly improving the flame retardant properties of the resin material.

[0070] It should be noted that, in this document, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or apparatus; although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A high thermal conductivity insulating resin, characterized in that: The insulating resin comprises the following raw materials by weight: 30-50 parts of epoxy resin; 40-60 parts of organic modified boron nitride; 20-30 parts of anhydride curing agent; The preparation method of the organically modified boron nitride is: S1. Dispersing boron nitride in a sodium hydroxide aqueous solution, then adding the solution to a hydrothermal reactor, and reacting at 120-130° C. for 20-24 hours to obtain hydroxylated boron nitride; S2. Add hydroxylated boron nitride to the toluene solution, stir for 20-30 minutes, then dropwise add 3-aminopropyltriethoxysilane, raise the temperature to 110-120° C. under nitrogen protection, and reflux for 10-12 hours to obtain aminoated boron nitride; S3, adding the amino boron nitride to the acetonitrile solution, adding potassium iodide and potassium carbonate under nitrogen protection, and then adding benzyl chloride dropwise, raising the temperature to 50-60°C, and reacting for 3-4h to obtain modified amino boron nitride; S4, dispersing the modified amino boron nitride in an aqueous solution of aminotrimethylenephosphonic acid, heating to 60-70° C., and reacting for 2-3 hours to obtain organically modified boron nitride; The insulating resin is prepared by a segmented curing process, which specifically includes the following steps: epoxy resin, organic modified boron nitride, and anhydride curing agent are uniformly mixed according to weight ratio, hot-pressed and then cured for the first time, then heated and cured for the second time, and cooled to obtain the insulating resin; the temperature of the first curing is 80-100°C and the time is 9-10 hours; the temperature of the second curing is 120-140°C and the time is 5-6 hours.

2. The high thermal conductivity insulating resin according to claim 1, characterized in that: The epoxy resin is one of bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, and novolac epoxy resin, or a mixture of several of them.

3. The high thermal conductivity insulating resin according to claim 1, characterized in that: The acid anhydride curing agent is one of phthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride and pyromellitic anhydride, or a mixture of several of them.

4. The high thermal conductivity insulating resin according to claim 1, characterized in that: The mass ratio of boron nitride to sodium hydroxide in step S1 is 1:20-25; the concentration of the sodium hydroxide aqueous solution is 4-5 mol / mL; and the mass ratio of hydroxylated boron nitride to 3-aminopropyltriethoxysilane in step S2 is 1:0.3-0.

5.

5. The high thermal conductivity insulating resin according to claim 1, characterized in that: The mass ratio of the amination boron nitride, benzyl chloride, potassium carbonate, and potassium iodide in step S3 is 1:0.8-1.0:1.3-1.5:0.6-0.

8.

6. The high thermal conductivity insulating resin according to claim 1, characterized in that: The mass ratio of the modified amino-boron nitride to aminotrimethylenephosphonic acid in step S4 is 1:0.6-0.8; the concentration of the aminotrimethylenephosphonic acid aqueous solution is 0.1-0.15 mol / L.

7. The method for preparing a high thermal conductive insulating resin according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: uniformly mixing epoxy resin, organic modified boron nitride and anhydride curing agent according to weight ratio, performing a first curing after hot pressing, then heating for a second curing, and obtaining insulating resin after cooling; the temperature of the first curing is 80-100°C and the time is 9-10 hours; the temperature of the second curing is 120-140°C and the time is 5-6 hours.

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