An electronic potting compound for packaging new energy power systems and its preparation method

Abstract

This invention discloses an electronic potting compound for encapsulating new energy power systems and its preparation method, belonging to the field of adhesive preparation technology. The electronic potting compound for encapsulating new energy power systems consists of component A and component B. Component A includes polypropylene glycol, dicyclohexylmethane diisocyanate, hydroxyl-terminated polydimethylsiloxane, bismuth-zinc composite catalyst, N,N-dimethylethanolamine, porous alumina supported filler, composite halogen-free flame retardant, thixotropic agent, defoamer, and surface-modified calcium sulfate whisker fibers. Component B includes polypropylene glycol and dicyclohexylmethane diisocyanate. The electronic potting compound prepared by this invention exhibits good thermal conductivity and electromagnetic shielding capabilities after curing, while also possessing high mechanical strength.

Description

Technical Field

[0001] This invention discloses an electronic potting compound for packaging new energy power systems and its preparation method, belonging to the field of adhesive preparation technology. Background Technology

[0002] With the rapid development of new energy power systems, the performance requirements for potting compounds in power electronic equipment such as photovoltaic inverters, energy storage converters, and wind power converters are becoming increasingly stringent. These devices operate in complex electromagnetic environments and generate a large amount of heat, requiring potting compounds to have good thermal conductivity, electromagnetic compatibility, and long-term reliability.

[0003] The prior art with publication number CN110144190B discloses an addition-type high thermal conductivity organosilicon electronic potting compound, which uses graphene-modified fillers to improve thermal conductivity and lubrication, but does not solve the electromagnetic shielding problem; the prior art with publication number CN117247762A discloses a low dielectric electronic potting compound, which focuses on improving dielectric properties without addressing thermal conductivity requirements, and its tensile strength is also low, only 0.5~0.9MPa; the prior art with publication number CN114774073A discloses an organosilicon electronic potting compound and its preparation method, which obtains a low volume shrinkage rate and excellent flowability by introducing aluminized hollow glass microspheres and organosilicon oligomer pretreated hollow glass microspheres into the potting compound. Although the coating structure filler improves the dispersibility to a certain extent, the preparation process is complex, and the coating layer may fall off during long-term use, affecting the performance durability.

[0004] In summary, existing electronic potting compounds generally suffer from limited functionality and complex processes. Therefore, it is necessary to develop a new technical solution that fundamentally addresses filler dispersion and functional integration. Summary of the Invention

[0005] In order to solve the above-mentioned problems in the prior art, the present invention provides an electronic potting compound for packaging new energy power systems and its preparation method, and achieves the following objectives: to prepare an electronic potting compound with good thermal conductivity and electromagnetic shielding ability, as well as high mechanical strength.

[0006] To achieve the above objectives, the following technical solution is adopted:

[0007] This invention provides an electronic potting compound for packaging new energy power systems, comprising component A and component B.

[0008] The raw materials of component A, by weight, include: 95-105 parts of polypropylene glycol, 19-24 parts of dicyclohexylmethane diisocyanate (HMDI), 7-10 parts of hydroxyl-terminated polydimethylsiloxane, 0.1-0.15 parts of bismuth-zinc composite catalyst, 0.03-0.05 parts of N,N-dimethylethanolamine (DMEA), 24-30 parts of porous alumina supported filler, 25-30 parts of composite halogen-free flame retardant, 2-3 parts of thixotropic agent, 0.5-1 part of defoamer, and 6-8 parts of surface-modified calcium sulfate whisker fibers.

[0009] The polypropylene glycol used is PPG-2000 with a hydroxyl value of 56±2 mgKOH / g.

[0010] The dicyclohexylmethane diisocyanate has an NCO content of 30-32%.

[0011] The bismuth-zinc composite catalyst is designated as BCAT-E16.

[0012] The porous alumina-supported filler comprises, by weight, 80-84 parts porous alumina, 31-36 parts zinc nitrate, 25-32 parts ferric nitrate, and 45-55 parts water.

[0013] The porous alumina has a particle size of 20-50 µm and a specific surface area of ​​100-200 m². 2 / g

[0014] The surface-modified calcium sulfate whisker fiber is made from calcium sulfate whiskers, silane coupling agent KH-550, and anhydrous ethanol. The mass ratio of calcium sulfate whiskers, KH-550, and anhydrous ethanol is 10:(1~2):(50~55).

[0015] The calcium sulfate whiskers have a length of 20-30 μm and an aspect ratio of 15-20.

[0016] The thixotropic agent is fumed silica.

[0017] The defoamer used is an organosilicone defoamer.

[0018] The composite halogen-free flame retardant is obtained by compounding diphenyl phosphate, active aluminum hydroxide, and ammonium polyphosphate, with a mass ratio of diphenyl phosphate, active aluminum hydroxide, and ammonium polyphosphate of 1:2:(2~3).

[0019] The raw materials of component B, by weight, include: 30-34 parts of polypropylene glycol and 70-80 parts of dicyclohexylmethane diisocyanate.

[0020] This invention also provides a method for preparing electronic potting compound for packaging new energy power systems, comprising the following steps:

[0021] Step 1: Preparation of porous alumina supported filler

[0022] The raw materials used, by weight, include 80-84 parts porous alumina, 31-36 parts zinc nitrate, 25-32 parts ferric nitrate, and 45-55 parts water.

[0023] The porous alumina was dried at 120°C for 2 hours.

[0024] Add zinc nitrate and ferric nitrate to water and stir until completely dissolved to prepare an impregnation solution.

[0025] The prepared impregnation solution is dripped onto the surface of the dried porous alumina while the carrier is continuously stirred. After the dripping is completed, the wet material is sealed and left to stand for 2-4 hours. The impregnated material is then transferred to a drying oven and dried at 80°C for 4 hours. After drying, the material is transferred to a muffle furnace and calcined at 600-650°C for 2-3 hours to obtain the porous alumina loaded filler.

[0026] Step 2: Preparation of surface-modified calcium sulfate whisker fibers

[0027] The surface-modified calcium sulfate whisker fiber is made from calcium sulfate whiskers, silane coupling agent KH-550, and anhydrous ethanol. The mass ratio of calcium sulfate whiskers, silane coupling agent KH-550, and anhydrous ethanol is 10:(1~2):(50~55).

[0028] Calcium sulfate whiskers were acid-treated in dilute hydrochloric acid and stirred for 1-2 hours. The whiskers were then filtered out, rinsed with water until neutral, and dried at 120°C for 1 hour. A KH-550 ethanol solution was prepared using KH-550 and anhydrous ethanol, and the pH was adjusted to 9-10 with ammonia. The dried calcium sulfate whiskers were added, and the reaction was stirred for 2-2.5 hours. After the reaction was complete, the solid was filtered out and dried at 100°C for 2 hours to obtain surface-modified calcium sulfate whisker fibers. The dilute hydrochloric acid had a concentration of 10 wt% and was used in an amount 5-7 times the mass of the calcium sulfate whiskers.

[0029] Step 3: Preparation of Component A

[0030] The raw materials used, by weight, include: 95-105 parts of polypropylene glycol, 19-24 parts of dicyclohexylmethane diisocyanate, 7-10 parts of hydroxyl-terminated polydimethylsiloxane, 0.1-0.15 parts of bismuth-zinc composite catalyst, 0.03-0.05 parts of DMEA, 24-30 parts of porous alumina supported filler, 25-30 parts of composite halogen-free flame retardant, 2-3 parts of thixotropic agent, 0.5-1 part of defoamer, and 6-8 parts of surface-modified calcium sulfate whisker fibers.

[0031] Polypropylene glycol was added to a reactor and heated to 80°C. The mixture was then vacuum-dehydrated until the water content was less than or equal to 0.05%. After dehydration, high-purity nitrogen was introduced to release the vacuum, and the temperature was lowered to 60-65°C. Molten HMDI was added dropwise, and the mixture was stirred for 3-4 hours under nitrogen protection. Hydroxyl-terminated polydimethylsiloxane, bismuth-zinc composite catalyst, and DMEA were added, and the reaction continued for 1-2 hours. The mixture was then cooled to room temperature to obtain a modified polyurethane prepolymer. The modified polyurethane prepolymer was added to a vacuum mixer, followed by porous alumina-supported filler and a composite halogen-free flame retardant. The mixture was stirred at 1000-1200 r / min for 30 minutes at 70°C and a vacuum degree ≤-0.09 MPa. A thixotropic agent and defoamer were then added, and the mixture was stirred for 20 minutes. The temperature was lowered to below 45°C, and surface-modified calcium sulfate whisker fibers were added. The mixture was stirred at 400-500 r / min for 30 minutes to obtain component A. Component A was then sealed and stored at room temperature for later use.

[0032] Step 4: Preparation of Component B

[0033] The raw materials of component B, by weight, include: 31-36 parts of polypropylene glycol and 70-80 parts of HMDI.

[0034] Polypropylene glycol was added to the reactor, stirring was started, and the temperature was raised to 100~120℃. The vacuum degree was controlled at ≤-0.09MPa to dehydrate it to a moisture content of ≤0.05%. The temperature was allowed to drop to room temperature for later use. HMDI was added to the reaction vessel and heated to 50~60℃ under nitrogen protection to melt it. The dehydrated polypropylene glycol was added dropwise at a rate of 10mL / min. After the addition was completed, the temperature was raised to 85~90℃ and the reaction was stirred at a rate of 600 r / min for 4.5~5h to obtain component B. After component B cooled to room temperature, it was sealed and stored for later use.

[0035] This invention also provides an application of electronic potting compound for packaging new energy power systems, the application method of which is as follows:

[0036] Mix component A and component B at a mass ratio of 4~5:1 until homogeneous, degas under vacuum, and then pot. After potting, cure the potted part at 70~80℃ for 2~3 hours, then raise the temperature to 100~110℃ for 1.5~2 hours, and allow it to cool naturally to room temperature to obtain the cured part.

[0037] The beneficial effects of this invention are as follows:

[0038] The electronic potting compound for encapsulating new energy power systems of this invention possesses excellent thermal conductivity, electromagnetic shielding capability, and high mechanical strength. Its thermal conductivity is 1.61~1.78 W / m·K, its electromagnetic shielding effectiveness is 38.4~41.5 dB, and its volume resistivity is 2.9 × 10⁻⁶. 14 ~3.5×10 14Ω·cm, UL94 flame retardancy rating is V-0, and tensile strength is 12.4~14.5MPa.

[0039] This invention uses porous alumina as a carrier, with transition metal oxides, zinc oxide, and iron oxide loaded within its pores. The high specific surface area of ​​the porous carrier achieves high dispersion of the functional components, while the confinement effect of the pores prevents particle agglomeration. During the curing process of the potting compound, shear force causes the porous filler to disperse uniformly along the flow field, forming effective thermal conductivity and electromagnetic shielding pathways. The loaded zinc oxide is a semiconductor material; in an electromagnetic field, its internal charges undergo directional migration, but cannot move long distances to form an electric current. The migration process requires overcoming resistance, thus converting electromagnetic energy into heat energy. The loaded iron oxide is an important magnetic material; in an electromagnetic field, its magnetic dipoles rotate continuously with the direction of the magnetic field. This process also requires overcoming magnetic moment resistance, thus consuming electromagnetic energy.

[0040] This invention utilizes calcium sulfate whiskers as a three-dimensional network reinforcement, and modifies their surface with a silane coupling agent to improve interfacial compatibility with the resin matrix. The surface-modified calcium sulfate whisker fibers, as two-dimensional materials, are randomly distributed within the matrix, forming a complex scattering network that extends the electromagnetic wave propagation path and increases electromagnetic wave absorption and attenuation. The whisker fibers interlock within the matrix to form a three-dimensional network structure, effectively transferring and dispersing stress, enabling the potting compound to withstand greater tensile stress, preventing damage to the compound itself due to internal or external stress, improving the material's mechanical strength, and also providing auxiliary functions for thermal conductivity and electromagnetic shielding. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0042] Example 1: An electronic potting compound for packaging new energy power systems

[0043] An electronic potting compound for packaging new energy power systems is prepared through the following steps:

[0044] Step 1: Preparation of porous alumina supported filler

[0045] The porous alumina-supported filler comprises, by weight, 84 parts porous alumina, 35 parts zinc nitrate, 32 parts ferric nitrate, and 55 parts water.

[0046] Porous alumina was dried at 120℃ for 2 hours. Zinc nitrate and ferric nitrate were then added to water and stirred until completely dissolved to prepare an impregnation solution. The prepared impregnation solution was slowly dripped onto the dried porous alumina while the carrier was stirred. After the dripping was completed, the wet material was sealed and allowed to stand for 2 hours. The impregnated material was then transferred to a drying oven and dried at 80℃ for 4 hours. After drying, the material was transferred to a muffle furnace and calcined at 650℃ for 2 hours to obtain porous alumina-supported filler.

[0047] Step 2: Preparation of surface-modified calcium sulfate whisker fibers

[0048] The surface-modified calcium sulfate whisker fibers are made from calcium sulfate whiskers, silane coupling agent KH-550, and anhydrous ethanol, with a mass ratio of calcium sulfate whiskers, KH-550, and anhydrous ethanol of 10:1:50.

[0049] Calcium sulfate whiskers were acid-treated in dilute hydrochloric acid with a concentration of 10 wt%, and the amount of hydrochloric acid was 5 times the mass of the calcium sulfate whiskers. After stirring for 1 hour, the calcium sulfate whiskers were filtered out, rinsed with water until neutral, and dried at 120°C for 1 hour for later use. A KH-550 ethanol solution was prepared using KH-550 and anhydrous ethanol, and the pH was adjusted to 9 using ammonia. The dried calcium sulfate whiskers were added, and the reaction was stirred for 2.5 hours. After the reaction was completed, the solid was filtered out and dried at 100°C for 2 hours to obtain surface-modified calcium sulfate whisker fibers.

[0050] Step 3: Preparation of Component A

[0051] The raw materials of component A, by weight, include: 100 parts polypropylene glycol, 22 parts dicyclohexylmethane diisocyanate, 10 parts hydroxyl-terminated polydimethylsiloxane, 0.1 parts bismuth-zinc composite catalyst, 0.03 parts DMEA, 24 parts porous alumina supported filler, 30 parts composite halogen-free flame retardant, 2 parts thixotropic agent, 0.5 parts defoamer, and 6 parts surface-modified calcium sulfate whisker fibers. The composite halogen-free flame retardant is obtained by compounding diphenyl phosphate, activated aluminum hydroxide, and ammonium polyphosphate, wherein the mass ratio of diphenyl phosphate, activated aluminum hydroxide, and ammonium polyphosphate is 1:2:3.

[0052] Polypropylene glycol was added to a reactor and heated to 80°C. The mixture was then vacuum-dehydrated until the water content was less than or equal to 0.05%. After dehydration, high-purity nitrogen was introduced to release the vacuum. The temperature was lowered to 60°C, and molten HMDI was added dropwise. The mixture was stirred for 4 hours under nitrogen protection. Hydroxyl-terminated polydimethylsiloxane, a bismuth-zinc composite catalyst, and DMEA were added, and the reaction continued for 2 hours. The mixture was then cooled to room temperature to obtain a modified polyurethane prepolymer. The modified polyurethane prepolymer was added to a vacuum mixer, followed by porous alumina-supported filler and a composite halogen-free flame retardant. The mixture was stirred at 1000 r / min for 30 minutes at 70°C and a vacuum degree ≤-0.09 MPa. A thixotropic agent and an antifoaming agent were then added, and the mixture was stirred for 20 minutes. The temperature was lowered to below 45°C, and surface-modified calcium sulfate whisker fibers were added. The mixture was stirred at 400 r / min for 30 minutes to obtain component A. Component A was then sealed and stored at room temperature for later use.

[0053] Step 4: Preparation of Component B

[0054] The raw materials of component B, by weight, include: 32 parts of polypropylene glycol and 75 parts of HMDI.

[0055] Polypropylene glycol was added to the reactor, stirring was started, and the temperature was raised to 100°C. The vacuum degree was controlled at ≤-0.09MPa to dehydrate the polypropylene glycol until the water content was ≤0.05%. The mixture was then allowed to cool to room temperature for later use. HMDI was added to the reaction vessel and heated to 60°C under nitrogen protection to melt it. The dehydrated polypropylene glycol was added dropwise at a rate of 10mL / min. After the addition was completed, the temperature was raised to 90°C, and the mixture was stirred at a rate of 600r / min for 4.5h to obtain component B. After component B cooled to room temperature, it was sealed and stored for later use.

[0056] An application of an electronic potting compound for packaging new energy power systems is described below:

[0057] Component A and component B are mixed evenly at a mass ratio of 4:1, degassed under vacuum, and then potted. After potting, the potted part is first cured at 70℃ for 3 hours, then heated to 100℃ for 2 hours, and then cooled naturally to room temperature to obtain the cured part.

[0058] Example 2: An electronic potting compound for packaging new energy power systems

[0059] An electronic potting compound for packaging new energy power systems is prepared through the following steps:

[0060] Step 1: Preparation of porous alumina supported filler

[0061] The porous alumina-supported filler comprises, by weight, 80 parts porous alumina, 31 parts zinc nitrate, 25 parts ferric nitrate, and 45 parts water.

[0062] Porous alumina was dried at 120℃ for 2 hours. Zinc nitrate and ferric nitrate were then added to water and stirred until completely dissolved to prepare an impregnation solution. The prepared impregnation solution was slowly dripped onto the dried porous alumina while the carrier was stirred. After the dripping was completed, the wet material was sealed and allowed to stand for 2 hours. The impregnated material was then transferred to a drying oven and dried at 80℃ for 4 hours. After drying, the material was transferred to a muffle furnace and calcined at 600℃ for 2 hours to obtain porous alumina-supported filler.

[0063] Step 2: Preparation of surface-modified calcium sulfate whisker fibers

[0064] The surface-modified calcium sulfate whisker fibers are made from calcium sulfate whiskers, silane coupling agent KH-550, and anhydrous ethanol, with a mass ratio of calcium sulfate whiskers, KH-550, and anhydrous ethanol of 10:2:55.

[0065] Calcium sulfate whiskers were acid-treated in dilute hydrochloric acid (10 wt%), with the amount being 5 times the mass of the calcium sulfate whiskers. After stirring for 1-2 hours, the calcium sulfate whiskers were filtered out and rinsed with water until neutral. The calcium sulfate whiskers were then dried at 120°C for 1 hour for later use. A KH-550 ethanol solution was prepared using KH-550 and anhydrous ethanol, and the pH was adjusted to 10 using ammonia. The dried calcium sulfate whiskers were then added, and the reaction was stirred for 2.5 hours. After the reaction was completed, the solid was filtered out and dried at 100°C for 2 hours to obtain surface-modified calcium sulfate whisker fibers.

[0066] Step 3: Preparation of Component A

[0067] The raw materials of component A, by weight, include: 105 parts polypropylene glycol, 24 parts dicyclohexylmethane diisocyanate, 10 parts hydroxyl-terminated polydimethylsiloxane, 0.15 parts bismuth-zinc composite catalyst, 0.05 parts DMEA, 30 parts porous alumina supported filler, 25 parts composite halogen-free flame retardant, 2 parts thixotropic agent, 1 part defoamer, and 8 parts surface-modified calcium sulfate whisker fibers. The composite halogen-free flame retardant is obtained by compounding diphenyl phosphate, activated aluminum hydroxide, and ammonium polyphosphate, wherein the mass ratio of diphenyl phosphate, activated aluminum hydroxide, and ammonium polyphosphate is 1:2:3.

[0068] Polypropylene glycol was added to a reactor and heated to 80°C. The mixture was then vacuum-dehydrated until the water content was less than or equal to 0.05%. After dehydration, high-purity nitrogen was introduced to release the vacuum. The temperature was lowered to 65°C, and molten HMDI was added dropwise. The mixture was stirred and reacted for 33 hours under nitrogen protection. Hydroxyl-terminated polydimethylsiloxane, bismuth-zinc composite catalyst, and DMEA were added, and the reaction continued for 1 hour. The mixture was then cooled to room temperature to obtain a modified polyurethane prepolymer. The modified polyurethane prepolymer was added to a vacuum mixer, followed by porous alumina-supported filler and a composite halogen-free flame retardant. The mixture was stirred at 1000 r / min for 30 minutes at 70°C and a vacuum degree ≤-0.09 MPa. A thixotropic agent and defoamer were then added, and the mixture was stirred for 20 minutes. The temperature was lowered to below 45°C, and surface-modified calcium sulfate whisker fibers were added. The mixture was stirred at 500 r / min for 30 minutes to obtain component A. Component A was then sealed and stored at room temperature for later use.

[0069] Step 4: Preparation of Component B

[0070] The raw materials of component B, by weight, include: 34 parts of polypropylene glycol and 80 parts of HMDI.

[0071] Polypropylene glycol was added to the reactor, stirring was started, and the temperature was raised to 120°C. The vacuum degree was controlled at ≤-0.09MPa to dehydrate the polypropylene glycol until the moisture content was ≤0.05%. The mixture was then allowed to cool to room temperature for later use. HMDI was added to the reaction vessel and heated to 60°C under nitrogen protection to melt it. The dehydrated polypropylene glycol was then added dropwise at a rate of 10mL / min. After the addition was complete, the temperature was raised to 85°C, and the mixture was stirred at a rate of 600r / min for 5 hours to obtain component B. After component B cooled to room temperature, it was sealed and stored for later use.

[0072] An application of an electronic potting compound for packaging new energy power systems is described below:

[0073] Component A and component B are mixed evenly at a mass ratio of 5:1, vacuum degassed, and then potted. After potting, the potted part is first cured at 80℃ for 2 hours, then heated to 110℃ for 1.5 hours, and then naturally cooled to room temperature to obtain the cured part.

[0074] Example 3: An electronic potting compound for packaging new energy power systems

[0075] An electronic potting compound for packaging new energy power systems is prepared through the following steps:

[0076] Step 1: Preparation of porous alumina supported filler

[0077] The porous alumina-supported filler comprises, by weight, 80 parts porous alumina, 31 parts zinc nitrate, 30 parts ferric nitrate, and 45 parts water.

[0078] Porous alumina was dried at 120℃ for 2 hours. Zinc nitrate and ferric nitrate were then added to water and stirred until completely dissolved to prepare an impregnation solution. The prepared impregnation solution was slowly dripped onto the dried porous alumina while the carrier was stirred. After the dripping was completed, the wet material was sealed and allowed to stand for 4 hours. The impregnated material was then transferred to a drying oven and dried at 80℃ for 4 hours. After drying, the material was transferred to a muffle furnace and calcined at 600~650℃ for 2~3 hours to obtain porous alumina-supported filler.

[0079] Step 2: Preparation of surface-modified calcium sulfate whisker fibers

[0080] The surface-modified calcium sulfate whisker fibers are made from calcium sulfate whiskers, silane coupling agent KH-550, and anhydrous ethanol, with a mass ratio of calcium sulfate whiskers, KH-550, and anhydrous ethanol of 10:2:50.

[0081] Calcium sulfate whiskers were acid-treated by adding dilute hydrochloric acid with a concentration of 10 wt% and an amount 7 times the mass of the calcium sulfate whiskers. After stirring for 2 hours, the calcium sulfate whiskers were filtered out, rinsed with water until neutral, and dried at 120°C for 1 hour for later use. A KH-550 ethanol solution was prepared by mixing KH-550 with anhydrous ethanol, and the pH was adjusted to 10 with ammonia. The dried calcium sulfate whiskers were added, and the reaction was stirred for 2 hours. After the reaction was completed, the solid was filtered out and dried at 100°C for 2 hours to obtain surface-modified calcium sulfate whisker fibers.

[0082] Step 3: Preparation of Component A

[0083] The raw materials of component A, by weight, include: 100 parts polypropylene glycol, 20 parts dicyclohexylmethane diisocyanate, 8 parts hydroxyl-terminated polydimethylsiloxane, 0.15 parts bismuth-zinc composite catalyst, 0.03 parts DMEA, 30 parts porous alumina supported filler, 30 parts composite halogen-free flame retardant, 3 parts thixotropic agent, 0.5 parts defoamer, and 8 parts surface-modified calcium sulfate whisker fibers. The composite halogen-free flame retardant is obtained by compounding diphenyl phosphate, activated aluminum hydroxide, and ammonium polyphosphate, wherein the mass ratio of diphenyl phosphate, activated aluminum hydroxide, and ammonium polyphosphate is 1:2:2.

[0084] Polypropylene glycol was added to a reactor and heated to 80°C. The mixture was then vacuum-dehydrated until the water content was less than or equal to 0.05%. After dehydration, high-purity nitrogen was introduced to release the vacuum. The temperature was lowered to 60°C, and molten HMDI was added dropwise. The mixture was stirred for 3 hours under nitrogen protection. Hydroxyl-terminated polydimethylsiloxane, bismuth-zinc composite catalyst, and DMEA were added, and the reaction continued for 2 hours. The mixture was cooled to room temperature to obtain a modified polyurethane prepolymer. The modified polyurethane prepolymer was added to a vacuum mixer, followed by porous alumina-supported filler and a composite halogen-free flame retardant. The mixture was stirred at 1200 r / min for 30 minutes at 70°C and a vacuum degree ≤-0.09 MPa. A thixotropic agent and defoamer were then added, and the mixture was stirred for 20 minutes. The temperature was lowered to below 45°C, and surface-modified calcium sulfate whisker fibers were added. The mixture was stirred at 500 r / min for 30 minutes to obtain component A. Component A was then sealed and stored at room temperature for later use.

[0085] Step 4: Preparation of Component B

[0086] The raw materials of component B, by weight, include: 32 parts of polypropylene glycol and 70 parts of HMDI.

[0087] Polypropylene glycol was added to the reactor, stirring was started, and the temperature was raised to 120°C. The vacuum degree was controlled at ≤-0.09MPa to dehydrate the polypropylene glycol until the moisture content was ≤0.05%. The mixture was then allowed to cool to room temperature for later use. HMDI was added to the reaction vessel and heated to 50°C under nitrogen protection to melt it. The dehydrated polypropylene glycol was then added dropwise at a rate of 10mL / min. After the addition was complete, the temperature was raised to 85°C, and the mixture was stirred at a rate of 600r / min for 5 hours to obtain component B. After component B cooled to room temperature, it was sealed and stored for later use.

[0088] An application of an electronic potting compound for packaging new energy power systems is described below:

[0089] Component A and component B are mixed evenly at a mass ratio of 4:1, degassed under vacuum, and then potted. After potting, the potted part is first cured at 80℃ for 2 hours, then heated to 100℃ for 2 hours, and then cooled naturally to room temperature to obtain the cured part.

[0090] Example 4: An electronic potting compound for packaging new energy power systems

[0091] An electronic potting compound for packaging new energy power systems is prepared through the following steps:

[0092] Step 1: Preparation of porous alumina supported filler

[0093] The porous alumina-supported filler comprises, by weight, 82 parts porous alumina, 36 parts zinc nitrate, 32 parts ferric nitrate, and 50 parts water.

[0094] Porous alumina was dried at 120℃ for 2 hours. Zinc nitrate and ferric nitrate were then added to water and stirred until completely dissolved to prepare an impregnation solution. The prepared impregnation solution was slowly dripped onto the dried porous alumina while the carrier was stirred. After the dripping was completed, the wet material was sealed and allowed to stand for 4 hours. The impregnated material was then transferred to a drying oven and dried at 80℃ for 4 hours. After drying, the material was transferred to a muffle furnace and calcined at 600℃ for 3 hours to obtain porous alumina-supported filler.

[0095] Step 2: Preparation of surface-modified calcium sulfate whisker fibers

[0096] The surface-modified calcium sulfate whisker fibers are made from calcium sulfate whiskers, silane coupling agent KH-550, and anhydrous ethanol, with a mass ratio of calcium sulfate whiskers, KH-550, and anhydrous ethanol of 10:1:50.

[0097] Calcium sulfate whiskers were acid-treated in dilute hydrochloric acid with a concentration of 10 wt% and an amount 5 times the mass of the calcium sulfate whiskers. After stirring for 1 hour, the calcium sulfate whiskers were filtered out, rinsed with water until neutral, and dried at 120°C for 1 hour for later use. A KH-550 ethanol solution was prepared using KH-550 and anhydrous ethanol, and its pH was adjusted to 9 using ammonia. The dried calcium sulfate whiskers were added, and the reaction was stirred for 2 hours. After the reaction was completed, the solid was filtered out and dried at 100°C for 2 hours to obtain surface-modified calcium sulfate whisker fibers.

[0098] Step 3: Preparation of Component A

[0099] The raw materials of component A, by weight, include: 95 parts polypropylene glycol, 19 parts dicyclohexylmethane diisocyanate, 7 parts hydroxyl-terminated polydimethylsiloxane, 0.1 parts bismuth-zinc composite catalyst, 0.03 parts DMEA, 24 parts porous alumina supported filler, 25 parts composite halogen-free flame retardant, 3 parts thixotropic agent, 0.5 parts defoamer, and 6 parts surface-modified calcium sulfate whisker fibers. The composite halogen-free flame retardant is obtained by compounding diphenyl phosphate, activated aluminum hydroxide, and ammonium polyphosphate, wherein the mass ratio of diphenyl phosphate, activated aluminum hydroxide, and ammonium polyphosphate is 1:2:3.

[0100] Polypropylene glycol was added to a reactor and heated to 80°C. The mixture was then vacuum-dehydrated until the water content was less than or equal to 0.05%. After dehydration, high-purity nitrogen was introduced to release the vacuum. The temperature was lowered to 60°C, and molten HMDI was added dropwise. The mixture was stirred for 3 hours under nitrogen protection. Hydroxyl-terminated polydimethylsiloxane, bismuth-zinc composite catalyst, and DMEA were added, and the reaction continued for 2 hours. The mixture was cooled to room temperature to obtain a modified polyurethane prepolymer. The modified polyurethane prepolymer was added to a vacuum mixer, followed by porous alumina-supported filler and a composite halogen-free flame retardant. The mixture was stirred at 1200 r / min for 30 minutes at 70°C and a vacuum degree ≤-0.09 MPa. A thixotropic agent and defoamer were then added, and the mixture was stirred for 20 minutes. The temperature was lowered to below 45°C, and surface-modified calcium sulfate whisker fibers were added. The mixture was stirred at 400 r / min for 30 minutes to obtain component A. Component A was then sealed and stored at room temperature for later use.

[0101] Step 4: Preparation of Component B

[0102] The raw materials of component B, by weight, include: 30 parts of polypropylene glycol and 70 parts of HMDI.

[0103] Polypropylene glycol was added to the reactor, stirring was started, and the temperature was raised to 100°C. The vacuum degree was controlled at ≤-0.09MPa to dehydrate the polypropylene glycol until the moisture content was ≤0.05%. The mixture was then allowed to cool to room temperature for later use. HMDI was added to the reaction vessel and heated to 60°C under nitrogen protection to melt it. The dehydrated polypropylene glycol was added dropwise at a rate of 10mL / min. After the addition was completed, the temperature was raised to 85°C, and the mixture was stirred at a rate of 600r / min for 4.5h to obtain component B. After component B cooled to room temperature, it was sealed and stored for later use.

[0104] The application of an electronic potting compound for packaging new energy power systems is as follows:

[0105] Component A and Component B are mixed evenly at a mass ratio of 5:1, degassed under vacuum, and then potted. After potting, the potted part is first cured at 70℃ for 3 hours, then heated to 110℃ for 1.5 hours, and then cooled naturally to room temperature to obtain the cured part.

[0106] Comparative Example 1

[0107] In component A, no porous alumina-supported filler is added; zinc oxide powder and iron oxide powder are used instead. The specific weight parts of zinc oxide powder and iron oxide powder are 10 parts zinc oxide and 10 parts iron oxide. The remaining raw material ratios and process conditions are the same as in Example 2.

[0108] Comparative Example 2

[0109] No surface-modified calcium sulfate whisker fibers were added to component A, and the remaining raw material ratios and process conditions were the same as in Example 2.

[0110] Performance testing

[0111] The performance of the potting compound cured samples obtained in Examples 1-4 and Comparative Examples 1-2 of this invention was tested. The test results are shown in Table 1. The test methods and standards are as follows:

[0112] Thermal conductivity: The test was conducted in accordance with the test method provided in standard GB / T 29313-2012 "Test Method for Thermal Conductivity of Electrical Insulation Materials".

[0113] Electromagnetic shielding effectiveness: The shielding effectiveness value was tested according to the test method provided in standard GB / T 30142-2013 "Measurement Method of Shielding Effectiveness of Planar Electromagnetic Shielding Materials".

[0114] Volume resistivity: The test was performed in accordance with the test method provided in standard GB / T 31838.3-2019 "Dielectric and resistive properties of solid insulating materials - Part 3: Resistive properties (DC method) - Surface resistance and surface resistivity".

[0115] Flame retardancy rating: Tested in accordance with standard UL94 "Test standard for flammability of plastic materials for equipment and electrical components" (2018).

[0116] Tensile strength: Tested in accordance with standard GB / T2567-2021 "Test Methods for Properties of Resin Castings".

[0117] Table 1 Performance test results of potting compound cured parts

[0118]

[0119] Analysis of the data in Table 1 shows that the electronic potting compound prepared in this invention has a thermal conductivity of 1.61~1.78 W / m·K, an electromagnetic shielding effectiveness of 38.4~41.5 dB, and a volume resistivity of 2.9 × 10⁻⁶. 14 ~3.5×10 14 The Ω·cm, UL94 flame retardancy rating of V-0, and tensile strength of 12.4~14.5 MPa indicate that the electronic potting compound of this invention has good thermal conductivity and electromagnetic shielding capabilities, as well as high mechanical strength. Comparative Example 1 did not use porous alumina-loaded filler; according to Table 1, its electromagnetic shielding performance, thermal conductivity, and flame retardancy are all lower than those of the embodiments. Comparative Example 2 did not use surface-modified calcium sulfate whisker fibers, and it can be seen that its thermal conductivity and mechanical strength are significantly negatively affected.

[0120] Obviously, there are many other possible implementation methods under the concept of this invention. It should be stated here that any changes made under the inventive concept of this invention will fall within the protection scope of this invention.

Claims

1. A new energy power system encapsulation electronic potting adhesive, which is composed of A component and B component, characterized in that: the raw materials of the A component include polypropylene glycol 95-105 parts, dicyclohexyl methane diisocyanate 19-24 parts, hydroxyl-terminated polydimethylsiloxane 7-10 parts, bismuth-zinc composite catalyst 0.1-0.15 parts, N,N-dimethyl ethanolamine 0.03-0.05 parts, porous alumina loading filler 24-30 parts, composite halogen-free flame retardant 25-30 parts, thixotropic agent 2-3 parts, defoaming agent 0.5-1 part, and surface-modified calcium sulfate whisker fiber 6-8 parts by weight; the porous alumina loading filler includes porous alumina 80-84 parts, zinc nitrate 31-36 parts, iron nitrate 25-32 parts, and water 45-55 parts by weight; the preparation method of the porous alumina loading filler comprises the following steps: preparing an impregnation solution by mixing zinc nitrate, iron nitrate and water, and adding the solution dropwise to the surface of dried porous alumina while continuously stirring the carrier, standing for 2-4 hours after the dropwise addition is completed, and then baking the dried product to obtain the porous alumina loading filler; the surface-modified calcium sulfate whisker fiber is prepared by mixing calcium sulfate whisker, silane coupling agent KH-550 and anhydrous ethanol in a mass ratio of 10: (1-2): (50-55); the raw materials of the B component include polypropylene glycol 31-36 parts and dicyclohexyl methane diisocyanate 70-80 parts by weight; the composite halogen-free flame retardant is prepared by compounding diphenyl phosphate, active aluminum hydroxide and ammonium polyphosphate in a mass ratio of 1:2: (2-3); the baking is performed at a temperature of 600-650 DEG C for 2-3 hours; and the preparation of the porous alumina loading filler, the surface-modified calcium sulfate whisker fiber, the A component and the B component is included. The acid treatment of the calcium sulfate whisker comprises the following steps: adding the calcium sulfate whisker into a dilute hydrochloric acid solution, and stirring for 1-2 hours; the mass of the dilute hydrochloric acid solution is 5-7 times that of the calcium sulfate whisker, and the concentration of the dilute hydrochloric acid solution is 10 wt%. The preparation of the A component comprises the following steps: vacuum dehydrating polypropylene glycol, controlling the temperature at 60-65 DEG C, adding molten dicyclohexyl methane diisocyanate dropwise, stirring for 3-4 hours under the protection of nitrogen, and then adding hydroxyl-terminated polydimethylsiloxane, bismuth-zinc composite catalyst and N,N-dimethyl ethanolamine, and continuing to react for 1-2 hours to obtain a modified polyurethane prepolymer. ​ ​ ​ 2. The electronic potting adhesive for new energy power system packaging according to claim 1, characterized in that: ​ 3. The electronic potting adhesive for new energy power system packaging according to claim 1, characterized in that: ​ 4. The preparation method of the electronic potting adhesive for new energy power system packaging according to any one of claims 1-3, characterized in that: ​ 5. The preparation method of the electronic potting glue for new energy power system packaging according to claim 4, characterized in that: ​ 6. The preparation method of the electronic potting glue for new energy power system packaging according to claim 5, characterized in that: ​ 7. The preparation method of the electronic potting glue for new energy power system packaging according to claim 4, characterized in that: ​ The modified polyurethane prepolymer, porous alumina loading filler, composite halogen-free flame retardant are added into a vacuum stirrer, and stirred at 1000-1200 r / min for 30 min under vacuum; then the thixotropic agent and defoaming agent are added in turn, and stirred for 20 min; cooled to 45℃, and then the surface modified calcium sulfate whisker fiber is added, and stirred at a speed of 400-500 r / min for 30 min to obtain the A component.

8. The method for preparing an electronic potting compound for packaging a new energy power system according to claim 7, characterized in that: The vacuum condition is that the vacuum degree is less than or equal to-0.09 MPa, and the temperature is 70℃.

9. The method for preparing the electronic potting adhesive for new energy power system packaging according to claim 4, characterized in that: The B component is prepared as follows: dicyclohexyl methane diisocyanate is added into a reaction kettle, and heated to melt under nitrogen protection, and then the dehydrated polypropylene glycol is added dropwise, and after the dropwise addition is completed, the temperature is increased to 85-90℃, and then stirred for 4.5-5 h to obtain the B component.

10. The application method of the electronic potting adhesive for new energy power system packaging according to claim 1, characterized in that: The application method is as follows: the A component and the B component are uniformly mixed according to the mass ratio (4-5):1, and then vacuum degassing is performed, and then poured and sealed, and then cured at 70-80℃ for 2-3 h, and then the temperature is increased to 100-110℃ for curing for 1.5-2 h.

Images