Black talc-based electronic packaging material and application thereof in intelligent low-altitude aircraft

Abstract

The invention discloses a black talc-based electronic packaging material and application thereof in an intelligent low-altitude aircraft, and relates to the technical field of packaging materials. The packaging material is prepared from the following raw materials in parts by weight: 30 to 50 parts of epoxy resin, 0.5 to 2 parts of modified coupling agent, 10 to 20 parts of black talcum powder, 3 to 10 parts of nano boron nitride, 10 to 12 parts of inorganic filler, 1 to 3 parts of flame retardant, 3 to 8 parts of curing agent and 0.1 to 0.5 part of curing accelerator. The packaging material prepared by the invention has excellent flame retardant property, tensile property and elongation at break.

Description

Technical Field

[0001] This invention relates to the field of packaging materials technology, specifically to black talc-based electronic packaging materials and their application in intelligent low-altitude aircraft. Background Technology

[0002] With the accelerated application of embodied intelligence technology in intelligent low-altitude aircraft, these vehicles are evolving from traditional "perception-control" systems to highly integrated "perception-decision-execution" systems, finding wide application in scenarios such as power line inspection, smart logistics, urban security, and emergency rescue. Embodied intelligent aircraft place higher demands on real-time environmental perception, autonomous decision-making, and high-precision execution capabilities. Their core electronics and power modules exhibit a development trend of high-density integration, miniaturization, and high-power output, placing more stringent requirements on the comprehensive performance of electronic packaging materials in terms of thermal conductivity, flame retardancy, insulation, and structural protection.

[0003] However, the epoxy resin-based encapsulation materials, aluminum nitride-filled resin systems, and some ceramic matrix composites currently widely used in engineering still have significant limitations in meeting the complex operating conditions of unibody intelligent aircraft. On the one hand, traditional epoxy resin encapsulation systems have a high proportion of organic components, which are prone to pyrolysis and carbonization under conditions such as transient temperature rise of high-power modules, arc discharge, and high-frequency pulses, resulting in insufficient flame retardant performance. On the other hand, although commonly used inorganic filler systems (such as aluminum nitride, beryllium oxide, and silicon micropowder) can improve the thermal conductivity and electrical insulation properties of materials through high filling ratios, they often lead to a significant increase in material brittleness, a decrease in elongation at break, and a deterioration in interfacial bonding performance, making the encapsulation materials prone to microcracks and interfacial failure under complex load conditions.

[0004] Chinese invention patent CN108588594A discloses an electronic insulating encapsulation material and its preparation method. The electronic insulating encapsulation material comprises the following raw materials in parts by weight: 10-15 parts diamond, 20-30 parts silicon carbide, 10-20 parts carbon fiber, 15-30 parts epoxy resin, 20-30 parts thermally conductive inorganic nanoparticles, 10-20 parts corrosion inhibitor, 10-15 parts toughening agent, 20-25 parts polyamide, and 30-40 parts matrix. It has good thermal conductivity and insulation properties, but its flame retardancy needs to be improved. Summary of the Invention

[0005] In view of the shortcomings of existing technologies, the purpose of this invention is to provide black talc-based electronic packaging materials and their application in intelligent low-altitude aircraft.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] Black talc-based electronic packaging material, comprising the following raw materials in parts by weight:

[0008] Epoxy resin: 30-50 parts, modified coupling agent: 0.5-2 parts, black talc powder: 10-20 parts, nano boron nitride: 3-10 parts, inorganic filler: 10-12 parts, flame retardant: 1-3 parts, curing agent: 3-8 parts, curing accelerator: 0.1-0.5 parts;

[0009] The modified coupling agent is prepared by the following method:

[0010] S1: N,N,N',N'-Tetracyclooxypropyl-4,4'-diaminodiphenylmethane reacts with 12-bromo-1-dodecanool to form a four-armed long-chain compound.

[0011] S2: A four-armed long-chain compound reacts with (2E,4Z)-decadienoic acid to form a polyolefin compound.

[0012] S3: Polyolefin compounds react with ammonia solution to form amino-modified polyolefin compounds.

[0013] S4: An amino-modified polyolefin compound reacts with γ-mercaptopropyltrimethoxysilane to generate a modified coupling agent.

[0014] In step S1, the molar ratio of N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane to 12-bromo-1-dodecanool is 1:(4.05-4.1).

[0015] In step S2, the molar ratio of the four-armed long-chain compound to (2E,4Z)-decadienoic acid is 1:(4.02-4.1).

[0016] In step S4, the molar ratio of the amino-modified polyolefin compound to γ-mercaptopropyltrimethoxysilane is 1:(8.05-8.1).

[0017] The flame retardant is prepared by the following method:

[0018] A1: Vanillin reacts with phosphorus oxychloride to form a trialdehyde compound.

[0019] A2: Dithieno[3,2-B:2',3'-D]thiophene-2-ylboronic acid reacts with 4-aminocatechol to form a borate ester compound.

[0020] A3: Trialdehyde compounds react with borate ester compounds to form intermediates.

[0021] A4: The intermediate reacts with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide to form a flame retardant.

[0022] In step A1, the molar ratio of vanillin to phosphorus oxychloride is 3.05:1; in step A2, the molar ratio of dithieno[3,2-B:2',3'-D]thiophene-2-ylboronic acid to 4-aminocatechol is 1:1.02.

[0023] In step A3, the molar ratio of the trialdehyde compound to the borate ester compound is 1:3.03; in step A4, the molar ratio of the intermediate to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide is 1:3.02.

[0024] The curing agent is one of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and pyromellitic anhydride; the curing accelerator is one of bisphenol A and resorcinol; and the inorganic filler is one of calcium carbonate and barium sulfate.

[0025] The preparation method of the encapsulation material is as follows: weigh each component according to the raw material composition, heat the epoxy resin, add the modified coupling agent, black talc powder, nano boron nitride, inorganic filler and flame retardant in sequence and mix evenly, then add curing agent and curing accelerator and vacuum degas, and finally cure and shape to obtain the product.

[0026] Application of black talc-based electronic packaging materials in intelligent low-altitude aircraft.

[0027] Due to the adoption of the above technical solutions, the beneficial effects of the present invention include:

[0028] The encapsulation material prepared by this invention has excellent flame retardant properties, tensile properties, and elongation at break. Detailed Implementation

[0029] The following description, in conjunction with specific embodiments, provides further details, but the present invention is not limited to these embodiments.

[0030] Example 1: Preparation of modified coupling agent:

[0031] S1: Under ice bath conditions, 400 ml of anhydrous toluene and 0.1 mol of N,N,N,N,-tetracyclooxypropyl-4,4-diaminodiphenylmethane were added to the reactor and stirred until homogeneous. Then, 4 g of boron trifluoride diethyl ether was added, followed by slow dropwise addition of 500 ml of toluene solution containing 0.405 mol of 12-bromo-1-dodecanool over 1 hour. After the addition was complete, the temperature was raised to 55°C and the reaction was allowed to proceed for 6 hours. The mixture was then cooled to 0°C, and saturated sodium carbonate solution was slowly added until the pH of the solution reached 7. The mixture was stirred at room temperature for 30 minutes, allowed to stand for separation, and the organic phase was washed three times with deionized water (150 ml each time) and once with 150 ml of saturated sodium chloride solution. The mixture was dried with 40 g of anhydrous sodium sulfate, filtered, distilled under reduced pressure at 60°C for 1 hour, and dried under vacuum at 60°C for 12 hours to obtain a four-armed long-chain compound. The reaction equation is shown below.

[0032]

[0033] Its 1H NMR data are as follows: 1 H NMR (400 MHz, Chloroform-d) δ 7.09 – 7.01 (m,4H), 6.73 – 6.63 (m, 4H), 4.09 (p, J = 0.8 Hz, 2H), 4.03 – 3.92 (m, 4H), 3.73(dd, J = 11.6, 5.5 HRMS (m / z):1483.6758[M+H] + .

[0034] S2: Under nitrogen protection, 800 ml of toluene, 0.402 mol of (2E,4Z)-decadienoic acid, 0.41 mol of DCC (N,N'-dicyclohexylcarbodiimide), and 0.01 mol of DMAP (4-dimethylaminopyridine) were added to the reactor. The mixture was stirred for 10 min, and then 0.1 mol of a four-arm long-chain compound was added. The reaction was carried out at room temperature for 12 h. The mixture was filtered, and the filtrate was washed successively with 200 ml of 2wt% dilute hydrochloric acid, 200 ml of saturated sodium bicarbonate solution, and 200 ml of saturated brine. The filtrate was dried over 30 g of anhydrous sodium sulfate, filtered, and distilled under reduced pressure at 65 °C for 1 h. The filtrate was purified by silica gel column chromatography (eluent: ethyl acetate / petroleum ether (V / V = 2:1), distilled under reduced pressure at 50 °C for 1.5 h, and dried under vacuum at 50 °C for 12 h to obtain the polyene compound. The reaction equation is shown below.

[0035]

[0036] Its 1H NMR data are as follows: 1H NMR (400 MHz, Chloroform-d) δ 7.46 (m, 4H),7.15 – 6.99 (m, 4H), 6.74 – 6.58 (m, 4H), 6.16 (m, 4H), 5.99 (dd, J = 15.6,0.8 Hz, 4H), 5.89 – 5.75 (m, 4H), 5.11 – 4.94 (m, 4H), 4.09 (p, J = 0.8 Hz,2H), 3.86 (dd, J = 11.9, 4.9 Hz, 4H), 3.73 – 3.38 (m, 28H), 2.13 (m, 8H),1.86 (tt, J = 7.5, 4.6 Hz, 8H), 1.60 – 1.18 (m, 96H), 0.94 – 0.81 (m, 12H); HRMS (m / z):2085.0718[M+H] + .

[0037] S3: Under nitrogen protection, 1500 ml of tetrahydrofuran and 0.1 mol of the polyene compound were added to a high-pressure reactor and stirred until well mixed. 165 ml of 7M ammonia-tetrahydrofuran solution was slowly added dropwise over 30 min. After the addition was complete, the mixture was heated to reflux and reacted for 24 h. The pH was adjusted to 10 with 5 wt% sodium hydroxide solution, and the mixture was extracted with ethyl acetate (250 ml × 3). The organic phases were combined, washed with 200 ml of saturated brine, dried over 40 g of anhydrous sodium sulfate, filtered, and purified by column chromatography (eluent: dichloromethane / methanol (V / V = 5:1)). The mixture was then distilled under reduced pressure at 50 °C for 2 h and dried under vacuum at 50 °C for 12 h to obtain the amino-modified polyene compound. The reaction equation is shown below:

[0038]

[0039] Its 1H NMR data are as follows: 1H NMR (400 MHz, Chloroform-d) δ 7.46 (m, 4H),7.13 – 6.99 (m, 4H), 6.72 – 6.60 (m, 4H), 6.16 (m, 4H), 5.99 (dd, J = 15.6,0.8 Hz, 4H), 5.88 – 5.78 (m, 4H), 5.05 – 4.97 (m, 4H), 4.09 (p, J = 0.8 Hz,2H), 3.86 (dd, J = 11.9, 4.9 Hz, 4H), 3.75 – 3.37 (m, 20H), 2.66 (tt, J =6.5, 5.2 Hz, 8H), 2.13 (m, J = 7.8, 5.6, 1.2 Hz, 8H), 1.61 – 1.19 (m, 112H), 0.95 – 0.80 (m, 12H); HRMS (m / z):1829.4821[M+H] + .

[0040] S4: Under nitrogen protection, add 1500 ml of anhydrous DMSO (dimethyl sulfoxide), 0.1 mol of amino-modified polyolefin compound, 0.805 mol of γ-mercaptopropyltrimethoxysilane, and 2.5 g of photoinitiator 184 to the reactor, stir and mix thoroughly, and at room temperature, with an intensity of 8.4 mW / cm². 2 After irradiation under a 365nm UV LED lamp for 8 hours, the mixture was distilled under reduced pressure at 70℃ for 2 hours. The solution was then slowly poured into 800ml of cold diethyl ether, stirred, and a precipitate formed. The precipitate was filtered, washed three times with 100ml of cold diethyl ether each time, and dried under vacuum at 50℃ for 12 hours to obtain the modified coupling agent. The reaction equation is shown below:

[0041]

[0042] Its 1H NMR data are as follows: 1H NMR (400 MHz, Chloroform-d) δ 7.17 – 6.98 (m,4H), 6.73 – 6.63 (m, 4H), 5.03 (tt, J = 5.8, 5.3 Hz, 4H), 4.09 (p, J = 0.8Hz, 2H), 3.87 (dd, J = 11.9, 5.3 Hz, 4H), 3.71 – 3.33 (m, 96H), 3.03 – 2.94(m, 4H), 2.80 – 2.41 (m, 32H), 1.88 (dt, J = 12.4, 6.3 Hz, 4H), 1.72 – 1.19(m, 140H), 0.92 – 0.86 (m, 12H), 0.82 – 0.76 (m, 16H); HRMS (m / z):3397.9546[M+H] + .

[0043] Example 2: Preparation of modified coupling agent:

[0044] S1: Under ice bath conditions, 400 ml of anhydrous toluene and 0.1 mol of N,N,N,N,-tetracyclooxypropyl-4,4-diaminodiphenylmethane were added to the reactor and stirred until well mixed. Then, 4 g of boron trifluoride ether was added, and 500 ml of toluene solution containing 0.408 mol of 12-bromo-1-dodecanool was slowly added dropwise over 1 hour. After the addition was complete, the temperature was raised to 60 °C and the reaction was allowed to proceed for 5.5 hours. The mixture was then cooled to 0 °C, and saturated sodium carbonate solution was slowly added until the pH of the solution reached 7. The mixture was stirred at room temperature for 30 minutes, allowed to stand and separate into layers, and the organic phase was washed three times with deionized water (150 ml each time) and once with 150 ml of saturated sodium chloride solution. The mixture was dried with 40 g of anhydrous sodium sulfate, filtered, distilled under reduced pressure at 60 °C for 1 hour, and dried under vacuum at 60 °C for 12 hours to obtain a four-armed long-chain compound.

[0045] S2: Under nitrogen protection, 800 ml of toluene, 0.406 mol of (2E,4Z)-decadienoic acid, 0.41 mol of DCC, and 0.01 mol of DMAP were added to the reactor and stirred for 10 min. Then, 0.1 mol of a four-arm long-chain compound was added, and the reaction was carried out at room temperature for 13 h. The mixture was filtered, and the filtrate was washed successively with 200 ml of 2 wt% dilute hydrochloric acid, 200 ml of saturated sodium bicarbonate solution, and 200 ml of saturated brine. The filtrate was dried over 30 g of anhydrous sodium sulfate, filtered, and distilled under reduced pressure at 65 °C for 1 h. The filtrate was purified by silica gel column chromatography (eluent: ethyl acetate / petroleum ether (V / V=2:1), distilled under reduced pressure at 50 °C for 1.5 h, and dried under vacuum at 50 °C for 12 h to obtain the polyene compound.

[0046] S3: Under nitrogen protection, 1500 ml of tetrahydrofuran and 0.1 mol of polyolefin compound were added to a high-pressure reactor and stirred until well mixed. 165 ml of 7M ammonia-tetrahydrofuran solution was slowly added dropwise over 30 min. After the addition was complete, the mixture was heated to reflux and reacted for 24 h. The pH was adjusted to 10 with 5 wt% sodium hydroxide solution. The mixture was extracted with ethyl acetate (250 ml × 3). The organic phases were combined, washed with 200 ml of saturated brine, dried over 40 g of anhydrous sodium sulfate, filtered, and purified by column chromatography (eluent: dichloromethane / methanol (V / V = 5:1)). The mixture was distilled under reduced pressure at 50 °C for 2 h and dried under vacuum at 50 °C for 12 h to obtain the amino-modified polyolefin compound.

[0047] S4: Under nitrogen protection, add 1500 ml anhydrous DMSO, 0.1 mol amino-modified polyolefin compound, 0.808 mol γ-mercaptopropyltrimethoxysilane, and 2.5 g photoinitiator 184 to the reactor, stir and mix thoroughly, and at room temperature, at an intensity of 8.4 mW / cm². 2 After irradiation under a 365nm ultraviolet LED lamp for 9 hours, the mixture was distilled under reduced pressure at 70℃ for 2 hours, slowly poured into 800ml of cold diethyl ether, stirred, and the precipitate was precipitated. The precipitate was filtered, washed three times with cold diethyl ether (100ml each time), and dried under vacuum at 50℃ for 12 hours to obtain the modified coupling agent.

[0048] Example 3: Preparation of modified coupling agent:

[0049] S1: Under ice bath conditions, 400 ml of anhydrous toluene and 0.1 mol of N,N,N,N-tetracyclooxypropyl-4,4-diaminodiphenylmethane were added to the reactor and stirred until well mixed. Then, 4 g of boron trifluoride ether was added, and 500 ml of toluene solution containing 0.41 mol of 12-bromo-1-dodecanool was slowly added dropwise over 1 hour. After the addition was complete, the temperature was raised to 65°C and the reaction was allowed to proceed for 5 hours. The mixture was then cooled to 0°C, and saturated sodium carbonate solution was slowly added until the pH of the solution reached 7. The mixture was stirred at room temperature for 30 minutes, allowed to stand and separate into layers, and the organic phase was washed three times with deionized water (150 ml each time) and once with 150 ml of saturated sodium chloride solution. The mixture was dried with 40 g of anhydrous sodium sulfate, filtered, distilled under reduced pressure at 60°C for 1 hour, and dried under vacuum at 60°C for 12 hours to obtain a four-armed long-chain compound.

[0050] S2: Under nitrogen protection, 800 ml of toluene, 0.41 mol of (2E,4Z)-decadienoic acid, 0.41 mol of DCC, and 0.01 mol of DMAP were added to the reactor and stirred for 10 min. Then, 0.1 mol of a four-arm long-chain compound was added, and the reaction was carried out at room temperature for 14 h. The mixture was filtered, and the filtrate was washed successively with 200 ml of 2 wt% dilute hydrochloric acid, 200 ml of saturated sodium bicarbonate solution, and 200 ml of saturated brine. The filtrate was dried over 30 g of anhydrous sodium sulfate, filtered, and distilled under reduced pressure at 65 °C for 1 h. The filtrate was purified by silica gel column chromatography (eluent: ethyl acetate / petroleum ether (V / V=2:1), distilled under reduced pressure at 50 °C for 1.5 h, and dried under vacuum at 50 °C for 12 h to obtain the polyene compound.

[0051] S3: Under nitrogen protection, 1500 ml of tetrahydrofuran and 0.1 mol of polyolefin compound were added to a high-pressure reactor and stirred until well mixed. 165 ml of 7M ammonia-tetrahydrofuran solution was slowly added dropwise over 30 min. After the addition was complete, the mixture was heated to reflux and reacted for 24 h. The pH was adjusted to 10 with 5 wt% sodium hydroxide solution. The mixture was extracted with ethyl acetate (250 ml × 3). The organic phases were combined, washed with 200 ml of saturated brine, dried over 40 g of anhydrous sodium sulfate, filtered, and purified by column chromatography (eluent: dichloromethane / methanol (V / V = 5:1)). The mixture was distilled under reduced pressure at 50 °C for 2 h and dried under vacuum at 50 °C for 12 h to obtain the amino-modified polyolefin compound.

[0052] S4: Under nitrogen protection, add 1500 ml anhydrous DMSO, 0.1 mol amino-modified polyolefin compound, 0.81 mol γ-mercaptopropyltrimethoxysilane, and 2.5 g photoinitiator 184 to the reactor, stir and mix thoroughly, and at room temperature, at an intensity of 8.4 mW / cm². 2 After irradiation under a 365nm ultraviolet LED lamp for 10 hours, the mixture was distilled under reduced pressure at 70℃ for 2 hours, slowly poured into 800ml of cold diethyl ether, stirred, and the precipitate was precipitated. The precipitate was filtered, washed three times with cold diethyl ether (100ml each time), and dried under vacuum at 50℃ for 12 hours to obtain the modified coupling agent.

[0053] Example 4: Preparation of flame retardant:

[0054] A1: Under nitrogen protection and in an ice bath, 200 ml of anhydrous dichloromethane and 0.305 mol vanillin were added to the reactor and stirred until well mixed. 0.31 mol triethylamine was slowly added dropwise over 20 min. After the addition was complete, 100 ml of a dichloromethane solution containing 0.1 mol phosphorus oxychloride was slowly added dropwise over 30 min. After the addition was complete, the mixture was brought to room temperature and reacted for 2 h. The reaction solution was then slowly poured into 200 ml of ice water and allowed to stand for separation. The aqueous phase was extracted three times with dichloromethane (80 ml each time). The organic phases were combined and washed successively with 80 ml of ice water, 80 ml of 5 wt% dilute hydrochloric acid, 80 ml of saturated sodium bicarbonate solution, and 80 ml of saturated brine. The mixture was dried over 40 g of anhydrous sodium sulfate, distilled under reduced pressure at 55 °C for 1 h, and dried under vacuum at 60 °C for 12 h to obtain the trialdehyde compound. The reaction equation is shown below:

[0055]

[0056] Its 1H NMR data are as follows: 1 H NMR (400 MHz, Chloroform-d) δ 9.86 (t, J = 1.5Hz, 3H), 7.66 (ddd, J = 8.4, 2.9, 1.5 Hz, 3H), 7.50 (dd, J = 1.9, 1.2 Hz, 3H), 7.35 (s, 3H), 3.86 (s, 9H); HRMS (m / z):501.0923[M+H] + .

[0057] A2: Add 300 ml tetrahydrofuran, 0.102 mol 4-aminocatechol, 0.1 mol dithiophene[3,2-B:2',3'-D]thiophene-2-ylboronic acid, and 5 g anhydrous magnesium sulfate to the reactor. Stir and mix well, react at room temperature for 20 h, filter, distill under reduced pressure at 45 °C for 1 h, then add 150 ml n-hexane, stir to precipitate, filter, and dry under vacuum at 60 °C for 12 h to obtain the borate ester compound; the reaction equation is shown below:

[0058]

[0059] Its 1H NMR data are as follows: 1H NMR (400 MHz, Chloroform-d) δ 8.12 (s, 1H), 7.44 (d, J = 1.5 Hz, 2H), 6.54 (d, J = 7.7 Hz, 1H), 6.44 (dd, J = 7.7, 2.1Hz, 1H), 6.35 (d, J = 2.1 Hz, 1H), 5.54 (s, 2H); HRMS (m / z):329.9865[M+H] + .

[0060] A3: Add 400 ml of anhydrous acetonitrile and 0.1 mol of trialdehyde compound to the reactor, stir and mix well, then add 10 g of 4A molecular sieve (sodium-A type molecular sieve), and slowly add 400 ml of anhydrous acetonitrile solution containing 0.303 mol of borate compound dropwise over 30 min. After the addition is complete, react at 45 °C for 3 h, filter, and distill the filtrate under reduced pressure at 45 °C for 1 h. Then add 300 ml of cold n-hexane, stir to precipitate, filter, wash three times with petroleum ether (50 ml of petroleum ether each time), and dry under vacuum at 60 °C for 12 h to obtain the intermediate; the reaction equation is shown below:

[0061]

[0062] Its 1H NMR data are as follows: 1 H NMR (400 MHz, Chloroform-d) δ 8.66 (dt, J =11.7, 4.5 Hz, 2H), 8.27 (t, J = 3.2 Hz, 1H), 8.12 (s, 3H), 7.49 – 7.40 (m,9H), 7.28 – 7.20 (m, 6H), 6.96 (dd, J = 7.8, 2.2 Hz, 3H), 6.81 – 6.67 (m,6H), 3.86 (s, 9H); HRMS (m / z):1433.0273[M+H] + .

[0063] A4: Under nitrogen protection, 1000 ml of xylene, 0.1 mol of intermediate, 0.01 mol of 1,8-diazabicycloundec-7-ene, and 0.302 mol of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide were added to a reactor. The mixture was stirred and stirred until homogeneous. The temperature was raised to 90°C and reacted for 12 h. After cooling to room temperature, the reaction solution was slowly added dropwise to 1200 ml of ice water over 1 h. A precipitate was formed by stirring, and the precipitated solid was collected by filtration. The solid was washed with 200 ml of deionized water and recrystallized three times with a mixed solution of toluene and anhydrous ethanol (toluene to anhydrous ethanol volume ratio 3:1, 300 ml of the mixed solution used each time). The solid was then dried under vacuum at 70°C for 12 h to obtain the flame retardant. The reaction equation is shown below:

[0064]

[0065] Its 1H NMR data are as follows: 1 H NMR (400 MHz, Chloroform-d) δ 8.42 (dd, J =7.5, 1.4 Hz, 3H), 8.25 (dd, J = 7.4, 1.2 Hz, 3H), 8.12 (s, 3H), 7.97 – 7.88(m, 6H), 7.72 – 7.66 (m, 3H), 7.61 (td, J = 7.3, 1.4 Hz, 3H), 7.48 – 7.31 (m,15H), 7.28 – 7.17 (m, 6H), 6.82 (dd, J = 8.1, 2.1 Hz, 3H), 6.67 (d, J = 8.1Hz, 3H), 6.47 (d, J = 2.1 Hz, 3H), 6.35 (d, J = 8.6 Hz, 3H), 5.43 (dt, J =8.6, 0.6 Hz, 3H), 3.86 (s, 9H); HRMS (m / z):2131.0347[M+H] + .

[0066] Example 5: Preparation of encapsulation materials:

[0067] (1) Weigh: epoxy resin: 300g, modified coupling agent (prepared in Example 1): 5g, black talc powder: 100g, nano boron nitride: 30g, inorganic filler (calcium carbonate): 100g, flame retardant (prepared in Example 4): 10g, curing agent (methylhexahydrophthalic anhydride): 30g, curing accelerator (bisphenol A): 1g;

[0068] (2) Add epoxy resin to the reactor and preheat at 60°C for 10 min. Then add modified coupling agent and stir at 800 rpm for 5 min. Then add black talc powder, nano boron nitride, inorganic filler and flame retardant in sequence and stir at 2000 rpm for 20 min. Add curing agent at 50°C and stir at 200 rpm for 5 min to make it evenly dispersed. Then add curing accelerator and stir at 500 rpm for 5 min to form a homogeneous encapsulation mixture. Degas under vacuum of -0.08 MPa for 10 min and then fill into the mold. Curing is carried out in a forced-air oven at 80°C for 2 h and at 120°C for 3 h. After cooling to room temperature, the encapsulation material is obtained.

[0069] Example 6: Preparation of encapsulation materials:

[0070] (1) Weigh: epoxy resin: 400g, modified coupling agent (prepared in Example 2): 10g, black talc powder: 150g, nano boron nitride: 60g, inorganic filler (barium sulfate): 110g, flame retardant (prepared in Example 4): 20g, curing agent (methyltetrahydrophthalic anhydride): 50g, curing accelerator (bisphenol A): 3g;

[0071] (2) Add epoxy resin to the reactor and preheat at 60°C for 10 min. Then add modified coupling agent and stir at 800 rpm for 5 min. Then add black talc powder, nano boron nitride, inorganic filler and flame retardant in sequence and stir at 2000 rpm for 20 min. Add curing agent at 50°C and stir at 200 rpm for 5 min to make it evenly dispersed. Then add curing accelerator and stir at 500 rpm for 5 min to form a homogeneous encapsulation mixture. Degas under vacuum of -0.08 MPa for 10 min and then fill into the mold. Curing is carried out in a forced-air oven at 80°C for 2 h and at 120°C for 3 h. After cooling to room temperature, the encapsulation material is obtained.

[0072] Example 7 Preparation of encapsulation material:

[0073] (1) Weigh: epoxy resin: 500g, modified coupling agent (prepared in Example 3): 20g, black talc powder: 200g, nano boron nitride: 100g, inorganic filler (barium sulfate): 120g, flame retardant (prepared in Example 4): 30g, curing agent (pyromellitic anhydride): 80g, curing accelerator (resorcinol): 5g;

[0074] (2) Add epoxy resin to the reactor and preheat at 60°C for 10 min. Then add modified coupling agent and stir at 800 rpm for 5 min. Then add black talc powder, nano boron nitride, inorganic filler and flame retardant in sequence and stir at 2000 rpm for 20 min. Add curing agent at 50°C and stir at 200 rpm for 5 min to make it evenly dispersed. Then add curing accelerator and stir at 500 rpm for 5 min to form a homogeneous encapsulation mixture. Degas under vacuum of -0.08 MPa for 10 min and then fill into the mold. Curing is carried out in a forced-air oven at 80°C for 2 h and at 120°C for 3 h. After cooling to room temperature, the encapsulation material is obtained.

[0075] Comparative Example 1

[0076] The raw material composition and preparation method of the black talc-based electronic packaging material are basically the same as those in Example 6, except that the modified coupling agent is replaced with an equal weight of the modified coupling agent prepared by the following method:

[0077] The preparation method of the modified coupling agent is basically the same as that in Example 2, except that N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane in step S1 is replaced with an equimolar amount of N-(epoxypropyl)-N-phenyl-epoxyethylene methylamine; the amount of 12-bromo-1-dodecanool in step S1 is 0.208 mol; the amount of (2E,4Z)-decadienoic acid in step S2 is 0.206 mol; the amount of ammonia solution in step S3 is 82 ml; and the amount of γ-mercaptopropyltrimethoxysilane in step S4 is 0.408 mol.

[0078] Comparative Example 2

[0079] The raw material composition and preparation method of the black talc-based electronic packaging material are basically the same as those in Example 6, except that the modified coupling agent is replaced with an equal weight of the modified coupling agent prepared by the following method:

[0080] The preparation method of the modified coupling agent is basically the same as that in Example 2, except that 12-bromo-1-dodecanool in step S1 is replaced with an equimolar amount of 6-bromohexanol.

[0081] Comparative Example 3

[0082] The raw material composition and preparation method of the black talc-based electronic packaging material are basically the same as those in Example 6, except that the modified coupling agent is replaced with an equal weight of the modified coupling agent prepared by the following method:

[0083] The preparation method of the modified coupling agent is basically the same as that in Example 2, except that (2E,4Z)-decadienoic acid in step S2 is replaced with an equimolar amount of 8-nonenoic acid.

[0084] Comparative Example 4

[0085] The raw material composition and preparation method of the black talc-based electronic packaging material are basically the same as those in Example 6, except that the modified coupling agent is replaced with an equal weight of the modified coupling agent prepared by the following method:

[0086] The preparation method of the modified coupling agent is basically the same as that in Example 2, except that γ-mercaptopropyltrimethoxysilane in step S4 is replaced with an equimolar amount of mercaptopropylmethyldimethoxysilane.

[0087] Comparative Example 5

[0088] The raw material composition and preparation method of the black talc-based electronic packaging material are basically the same as those in Example 6, except that the flame retardant is replaced with an equal weight of flame retardant prepared by the following method:

[0089] The preparation method of the flame retardant is basically the same as that in Example 4, except that phosphorus oxychloride in step A1 is replaced with an equimolar amount of ethyl phosphoric acid dichloride.

[0090] Comparative Example 6

[0091] The raw material composition and preparation method of the black talc-based electronic packaging material are basically the same as those in Example 6, except that the flame retardant is replaced with an equal weight of flame retardant prepared by the following method:

[0092] The preparation method of the flame retardant is basically the same as that in Example 4, except that the dithiophene[3,2-B:2',3'-D]thiophene-2-ylboronic acid in step A2 is replaced with an equimolar amount of thiophene[3,2-b]thiophene-2-boronic acid.

[0093] Comparative Example 7

[0094] The raw material composition and preparation method of the black talc-based electronic packaging material are basically the same as those in Example 6, except that the flame retardant is replaced with an equal weight of flame retardant prepared by the following method:

[0095] The preparation method of the flame retardant is basically the same as that in Example 4, except that the dithiophene[3,2-B:2',3'-D]thiophene-2-ylboronic acid in step A2 is replaced with an equimolar amount of 2,2'-bisthiophene-5-boronic acid.

[0096] Comparative Example 8

[0097] The raw material composition and preparation method of the black talc-based electronic packaging material are basically the same as those in Example 6, except that the flame retardant is replaced with an equal weight of flame retardant prepared by the following method:

[0098] The preparation method of the flame retardant is basically the same as that in Example 4, except that the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide in step A4 is replaced with an equimolar amount of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0099] The 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide used in the comparative examples and embodiments of this application was prepared by the following method:

[0100] Under nitrogen protection, 60 ml of toluene and 10.8 g of DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) were added to the reactor and stirred for 25 min to mix evenly. Then, 2.78 g of phosphorus pentasulfide was added, and the temperature was raised to 60 °C and reacted for 2 h. Another 2.78 g of phosphorus pentasulfide was added, and the temperature was lowered to 45 °C and reacted for 15 h. The mixture was then distilled under reduced pressure at 60 °C for 0.5 h. 100 ml of chloroform was added to dissolve the mixture, and 20 ml of saturated sodium bicarbonate solution was slowly added dropwise over 20 min. After the addition was complete, the mixture was stirred for another 30 min. The mixture was allowed to stand and separate into layers. The organic phase was then distilled under reduced pressure at 60 °C for 1 h and dried under vacuum at 70 °C for 2 h to obtain 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide.

[0101] The epoxy resin used in the embodiments and comparative examples of this application is bisphenol A type epoxy resin, model E-44, purchased from Sinopec Hunan Petrochemical Co., Ltd.; the black talc powder is model BT-5020, with a particle size uniformly distributed between 5-10μm, produced by Quanzhou Xufeng Powder Raw Material Co., Ltd.; the nano boron nitride is model MG-BN-50, with an average particle size of 50nm, produced by Shanghai Maoguo Nanotechnology Co., Ltd.

[0102] The encapsulation materials prepared in the examples and comparative examples were tested for flame retardancy, tensile strength, and elongation at break. The test results are shown in Table 1.

[0103] Sample preparation: The encapsulation materials prepared in the examples and comparative examples were placed in a forced-air drying oven and dried at 80℃ for 12 hours. After drying, the encapsulation materials were made into Type 1A standard samples (refer to GB / T1040.2-2022) using an injection molding machine. The parameters of each section of the injection molding machine were set as follows: the temperatures of zones one to five were set to 220℃, 230℃, 240℃, 240℃, and 245℃; the injection speed was 3.6 cm. 3 / s; the injection pressure is 80MPa, and the holding pressure is 80% of the injection pressure.

[0104] Tensile strength and elongation at break tests: Tensile properties were tested using a tensile testing machine (CTM2050). All specimens were subjected to tensile testing at a loading rate of 10 mm / min. The tensile strength and elongation at break of the specimens were calculated.

[0105] Tensile strength = maximum tensile force during the stretching process / cross-sectional area;

[0106] Elongation at break = (Length at break - Initial length) / Initial length × 100%.

[0107] Flame retardancy test: The flame retardancy test shall be conducted according to Test Method B, Vertical Burning Test, in GB / T 2408-2021.

[0108] Table 1. Test data of packaging material performance

[0109]

[0110] As can be seen from Table 1, the encapsulation material prepared in this application has excellent flame retardant properties, tensile properties, and elongation at break.

[0111] The modified coupling agent prepared in this application incorporates flexible alkyl chains, amino groups, thioether groups, and siloxane segments. These functional groups exhibit a significant synergistic effect in encapsulating materials, enhancing interfacial bonding and stress transfer, thereby effectively improving the tensile properties and elongation at break of the material. Specifically, the four-armed long-chain structure provides molecular flexibility, absorbing and dispersing localized stress under external forces to prevent stress concentration; the amino groups possess strong polarity, forming hydrogen bonds or coordination structures with hydroxyl, carbonyl, or epoxy groups in the resin, significantly enhancing interfacial bonding strength; the thioether groups form stable CS or S-Si bond crosslinking points under photoinitiation, improving stress transfer continuity; and the siloxane segments hydrolyze and condense during curing to form a Si-O-Si network structure, creating a strong chemical bridge between the organic matrix and inorganic filler interface, improving interfacial adhesion and inhibiting interfacial debonding. The synergistic effect of the multi-functional groups in the modified coupling agent achieves a synergistic enhancement of both the toughness and strength of the material. Comparative Example 1 altered the core amine skeleton, affecting the regularity and reaction uniformity of the four-arm structure, leading to a decrease in mechanical properties; Comparative Example 2 shortened the flexible chain length, reducing toughening and stress dispersion capabilities, thus decreasing the elongation at break; Comparative Example 3 reduced the number of double bonds, decreasing the crosslinking density and anchoring efficiency of subsequent photoclick reactions; Comparative Example 4 reduced the number of hydrolyzable methoxy groups in silanes, decreasing the interfacial bonding strength with inorganic fillers, thereby leading to a decrease in performance.

[0112] The flame retardant prepared in this invention consists of a phosphaphenanthrene sulfide framework, a boron aromatic heterocyclic structure, and thiophene and other fused heterocyclic structures. Specifically, the P=O and P=S bonds in the phosphaphenanthrene sulfide structure can cleave upon heating to generate phosphorus-containing active groups, capturing free radicals such as ·H and ·OH formed during combustion and inhibiting chain reactions in the flame. Simultaneously, the phosphorus-containing structure promotes rapid carbonization of the resin matrix at high temperatures, forming a continuous and dense carbon layer on the material surface, effectively isolating oxygen and heat transfer. The B–O bonds in the boron ester structure soften, vitrify, and undergo local cross-linking at high temperatures, forming a stable B–O–C inorganic network layer. This layer exhibits excellent thermal stability and ablation resistance, further enhancing the density and structural strength of the surface carbon layer. Furthermore, the introduced thiophene and dithiophene-thiophene fused heterocyclic structures possess excellent thermal stability and are more readily converted into aromatic carbon frameworks during thermal decomposition, significantly promoting the carbonization efficiency of the matrix material. Meanwhile, sulfur atoms in the thiophene ring can form stable sulfur oxides or sulfide residues at high temperatures, enhancing the density and mechanical strength of the condensed-phase carbon layer, thereby improving its heat insulation and oxygen barrier properties. Through the synergistic effect of multiple functional groups, the heat resistance and flame retardant properties of the encapsulation material are improved. In Comparative Example 8, the flame retardant used replaced P=S bonds with P=O bonds, losing the reinforcing effect of sulfur on the condensed-phase carbon layer and the gas-phase synergistic flame-retardant effect, resulting in a decrease in flame-retardant performance.

[0113] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A black talc-based electronic packaging material, characterized in that, The ingredients include the following parts by weight: Epoxy resin: 30-50 parts, modified coupling agent: 0.5-2 parts, black talc powder: 10-20 parts, nano boron nitride: 3-10 parts, inorganic filler: 10-12 parts, flame retardant: 1-3 parts, curing agent: 3-8 parts, curing accelerator: 0.1-0.5 parts; The modified coupling agent is prepared by the following method: S1: N,N,N',N'-Tetracyclooxypropyl-4,4'-diaminodiphenylmethane reacts with 12-bromo-1-dodecanool to form a four-armed long-chain compound. S2: A four-armed long-chain compound reacts with (2E,4Z)-decadienoic acid to form a polyolefin compound. S3: Polyolefin compounds react with ammonia solution to form amino-modified polyolefin compounds. S4: An amino-modified polyolefin compound reacts with γ-mercaptopropyltrimethoxysilane to generate a modified coupling agent.

2. The encapsulation material according to claim 1, characterized in that, In step S1, the molar ratio of N,N,N',N'-tetracyclooxypropyl-4,4'-diaminodiphenylmethane to 12-bromo-1-dodecanool is 1:(4.05-4.1).

3. The encapsulation material according to claim 1, characterized in that, In step S2, the molar ratio of the four-armed long-chain compound to (2E,4Z)-decadienoic acid is 1:(4.02-4.1).

4. The encapsulation material according to claim 1, characterized in that, In step S4, the molar ratio of the amino-modified polyolefin compound to γ-mercaptopropyltrimethoxysilane is 1:(8.05-8.1).

5. The encapsulation material according to claim 1, characterized in that, The flame retardant is prepared by the following method: A1: Vanillin reacts with phosphorus oxychloride to form a trialdehyde compound. A2: Dithieno[3,2-B:2',3'-D]thiophene-2-ylboronic acid reacts with 4-aminocatechol to form a borate ester compound. A3: Trialdehyde compounds react with borate ester compounds to form intermediates. A4: The intermediate reacts with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide to form a flame retardant.

6. The encapsulation material according to claim 5, characterized in that, In step A1, the molar ratio of vanillin to phosphorus oxychloride is 3.05:1; in step A2, the molar ratio of dithieno[3,2-B:2',3'-D]thiophene-2-ylboronic acid to 4-aminocatechol is 1:1.

02.

7. The encapsulation material according to claim 5, characterized in that, In step A3, the molar ratio of the trialdehyde compound to the borate ester compound is 1:3.03; in step A4, the molar ratio of the intermediate to 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-sulfide is 1:3.

02.

8. The encapsulation material according to claim 1, characterized in that, The curing agent is one of methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, and pyromellitic anhydride; the curing accelerator is one of bisphenol A and resorcinol; and the inorganic filler is one of calcium carbonate and barium sulfate.

9. The encapsulation material according to claim 1, characterized in that, The preparation method of the encapsulation material is as follows: weigh each component according to the raw material composition, heat the epoxy resin, add the modified coupling agent, black talc powder, nano boron nitride, inorganic filler and flame retardant in sequence and mix evenly, then add curing agent and curing accelerator and vacuum degas, and finally cure and shape to obtain the product.

10. The application of the encapsulation material according to any one of claims 1-9 in a smart low-altitude aircraft.

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