Modified epoxy resin pouring sealant and preparation method thereof

Abstract

The invention relates to the field of pouring sealants, and discloses a modified epoxy resin pouring sealant and a preparation method thereof, the pouring sealant comprises epoxy resin, a modified inorganic filler, a modified additive and an auxiliary agent; the modified inorganic filler is prepared by grafting a quaternized s-triazine derivative and an inorganic filler; the quaternized s-triazine derivative is prepared through the steps that 3, 5-diaminophenylboronic acid, cyanuric chloride, 3-chloropropyltrimethoxysilane and 1, 4-butanediamine are sequentially subjected to substitution to prepare a s-triazine derivative, then the s-triazine derivative reacts with N, N-dimethyl-1, 3-diaminopropane, and bromoethane is used for quaternization treatment. The modified additive is prepared from a modified bismaleimide monomer prepared from maleic anhydride and 5 (6)-amino-1-(4-aminophenyl)-1, 3, 3-trimethylindane and 1-methyl-4-isopropyl cyclohexene through a self-stabilization precipitation polymerization method, the prepared pouring sealant is high in tensile strength, good in impact resistance and good in mechanical property, and the prepared pouring sealant has the advantages of being good in mechanical property, good in mechanical property and good in mechanical property. Meanwhile, good heat resistance, flame retardance, dielectricity and antibacterial activity are achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of pouring sealant and specifically relates to a modified epoxy resin pouring sealant and a preparation method thereof. BACKGROUND

[0002] The pouring sealant is a liquid active compound composed of a resin matrix, a curing agent (or a cross-linking agent), a filler and the like, has flowability before curing, can be poured into and permeate into the gap inside an electronic device, and is cured into a thermosetting composite material under certain conditions to play the roles of bonding and fixing, waterproofing and moisture-proofing, dust-proofing and insulation, etc., wherein the epoxy resin pouring sealant has high bonding strength, good sealing stability, resistance to chemicals, weather and aging, and excellent comprehensive performance in mechanics and electricity, and is one of the most widely used pouring sealants for electronic devices.

[0003] However, the epoxy resin is a flammable material and produces a large amount of toxic gas during combustion, which seriously restricts its application in the field of electronic pouring, and the addition of a flame retardant is the most direct and simple method for improving the flame retardant performance of the epoxy resin pouring sealant, wherein the flame retardants can be divided into halogen-containing flame retardants and halogen-free flame retardants according to the types, the halogen-containing flame retardants emit a large amount of toxic smoke during combustion, causing a "secondary disaster", and the traditional halogen-free flame retardant system has problems such as low flame retardant efficiency, large addition amount and poor compatibility with the matrix material, which leads to a significant reduction in the mechanical performance of the material, in addition, the existing epoxy resin pouring sealant is relatively brittle and does not perform well in impact resistance, heat resistance and antibacterial performance, thereby limiting its application range. SUMMARY

[0004] To solve the problems mentioned in the background, the purpose of the present application is to provide a modified epoxy resin pouring sealant and a preparation method thereof, by adding modified inorganic fillers and modified additives, the prepared pouring sealant has high tensile strength, good impact resistance, and good heat resistance, flame retardant performance, dielectric performance and antibacterial performance.

[0005] The purpose of the present application can be achieved by the following technical solutions. A modified epoxy resin pouring sealant comprises the following components by weight: 70-95 parts of epoxy resin, 10-20 parts of modified inorganic filler, 2-6 parts of modified additive, 20-40 parts of curing agent, 1-3 parts of curing accelerator and 15-30 parts of diluent. The modified inorganic filler is prepared by grafting quaternary ammonium s-triazine derivative on the surface of inorganic filler through chemical reaction; the quaternary ammonium s-triazine derivative is prepared by substituting reaction of 3,5-diaminophenyl boronic acid with cyanuric chloride, then substituting reaction of 3-chloropropyl trimethoxysilane, preparation of s-triazine intermediate, then substituting reaction of 1,4-butanediamine as 'bridging agent' with s-triazine intermediate, preparation of s-triazine derivative, then substituting reaction of N,N-dimethyl-1,3-diaminopropane with s-triazine derivative and quaternary ammonium treatment with bromoethane; The modified additive is prepared by using maleic anhydride and 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindane as raw materials, using p-toluenesulfonic acid method to prepare modified bismaleimide monomer, then using 1-methyl-4-isopropylcyclohexene and modified bismaleimide monomer as monomer raw materials, using self-stabilizing precipitation polymerization method to polymerize.

[0006] Preferably, the preparation method of the modified inorganic filler comprises the following steps: ultrasonic dispersion of inorganic filler in anhydrous ethanol and deionized water, then addition of quaternary ammonium s-triazine derivative, stirring and reaction at 60-80℃ for 8-12h, after reaction completion, filtration, washing, drying to prepare modified inorganic filler; The inorganic filler is one or several compound of silicon powder, nano-silica, aluminum hydroxide, graphene oxide, talc powder, nano-titanium dioxide, aluminum oxide, montmorillonite and boron nitride.

[0007] Preferably, the preparation method of the quaternary ammonium s-triazine derivative comprises the following steps: I. cyanuric chloride and toluene solvent are taken in a reactor, the reaction temperature is maintained at -5-0℃, then 3,5-diaminophenyl boronic acid and toluene mixed solution are slowly added and stirred for 4-6h, triethylamine is added in batches during the reaction, after reaction completion, washing to neutral, drying of organic layer with anhydrous sodium sulfate, then concentration to prepare s-triazine monosubstituent; II. under nitrogen protection, s-triazine monosubstituent and N,N-dimethylformamide are taken in a reactor, 3-chloropropyl trimethoxysilane and triethylamine are added, stirring and reaction at 55-65℃ for 5-7h, after the reaction liquid is cooled to room temperature, slowly pour into vigorously stirred ice water, after extraction, the organic phase is washed, dried, rotary evaporated, column chromatography purified to prepare s-triazine intermediate; III. Take 1,4-butanediamine and acetone solvent in the reactor, after stirring uniform slowly drop the mixed solution of s-triazine intermediate and acetone, maintain the system reaction temperature 30~35℃, and the pH value of the reaction system is adjusted to 6~7 by using sodium hydroxide solution, continue to react 3~4h, after reaction by suction filtration, washing, drying, preparation of s-triazine derivative; IV. Take a small amount of s-triazine derivative multiple times added to N,N-dimethyl-1,3-diaminopropane, control the reaction temperature at 100~105℃, stirring reaction 4~6h, after the reaction liquid cooled to room temperature dissolved in toluene, and washed with saturated sodium chloride aqueous solution, the organic layer was dried with anhydrous sodium sulfate, suction filtration, rotary evaporation, preparation of modified s-triazine derivative; V. Take bromoethane added to the mixed solution of modified s-triazine derivative and acetone, heated to 55~60℃, stirring reaction 4~6h, after reaction by reduced pressure concentration, ethyl acetate recrystallization, preparation of quaternary ammonium s-triazine derivative.

[0008] Preferably, the step I in the mole ratio of cyanuric chloride and 3,5-diaminophenyl boronic acid is 1:1~1.1.

[0009] Preferably, the step II in the mole ratio of s-triazine monosubstituted and 3-chloropropyl trimethoxysilane is 1:1~1.2.

[0010] Preferably, the step III in the mole ratio of 1,4-butanediamine and s-triazine intermediate is 1:2~2.2.

[0011] Preferably, the preparation method of the modified additive comprises the following steps: ①Take maleic anhydride, N,N-dimethylacetamide and toluene in the reactor, after the maleic anhydride is completely dissolved, drop the mixed solution of 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindane and N,N-dimethylacetamide, room temperature for 2.5~3.5h, then add p-toluenesulfonic acid, heating to 110~115℃, incubation 4.5~5.5h, then add boiling water containing sodium bicarbonate, washed to neutral after extraction, rotary evaporation to remove the solvent and dry, preparation of modified bismaleimide monomer; ②Take modified bismaleimide monomer and cyclohexanone in the reactor, stirring after dissolving, add n-nonyl, 1-methyl-4-isopropyl cyclohexene and initiator dicumyl peroxide, purged with nitrogen for 30min to remove oxygen, then react at 125~130℃ for 5.5~6h, after reaction, wash away the unreacted, and use methyl tert-butyl ether to replace the solvent, then vacuum drying, preparation of modified additive.

[0012] Preferably, the addition ratio of the modified bismaleimide monomer, cyclohexanone, n-nonane, 1-methyl-4-isopropylcyclohexene and dicumyl peroxide in step ② is 0.65-0.7 g: 7-7.5 mL: 7-7.5 mL: 0.41-0.44 g: 0.025-0.03 g.

[0013] Preferably, the epoxy resin is one of bisphenol A type epoxy resin, furan epoxy resin, tetraglycidyl amine type epoxy resin; the curing agent is one or several complex of methyl hexahydrophthalic anhydride, diamino diphenyl sulfone, phthalic anhydride, 3-methyl tetrahydrophthalic anhydride; the accelerator is one or several complex of 1,8-diazabicyclo[5.4.0]undec-7-ene, 2-ethyl-4-methylimidazole, tertiary amine, dicyandiamide; the diluent is one or several complex of ethylene glycol diglycidyl ether, dodecyl glycidyl ether, neopentyl glycol diglycidyl ether.

[0014] The preparation method of the modified epoxy resin pouring sealant as described above comprises the following steps: S1, each component is weighed by weight parts, the epoxy resin and the modified additive are mixed and then preheated at 125-130 DEG C for 40-60 min to prepare a premix; S2, the system is cooled to 75-85 DEG C, the modified inorganic filler, the curing agent, the curing accelerator and the diluent are added into the premix and stirred uniformly to prepare a mixture; S3, the mixture is transferred to a grinder for grinding and dispersion, then defoaming under vacuum for 20-60 min, and then poured into a mold for high-temperature curing to prepare the modified epoxy resin pouring sealant.

[0015] The beneficial effects of the present application are: The present application utilizes the substitution reaction of 3,5-diaminophenyl boronic acid and one chlorine atom in cyanuric chloride to prepare a monosubstituted cyanuric chloride, then utilizes the substitution reaction of 3-chloropropyl trimethoxysilane and the ungrafted amino group in the monosubstituted cyanuric chloride to prepare a cyanuric chloride intermediate, then utilizes 1,4-butanediamine as a bridging agent to make the amino groups at both ends of the 1,4-butanediamine respectively substitute the second chlorine atom in the cyanuric chloride intermediate to prepare a cyanuric chloride derivative, then utilizes the substitution reaction of N,N-dimethyl-1,3-diaminopropane and the remaining chlorine atom in the cyanuric chloride derivative to prepare a modified cyanuric chloride derivative, and utilizes bromoethane to quaternize the modified cyanuric chloride derivative to prepare a quaternary ammonium cyanuric chloride derivative.

[0016] The quaternary ammonium homotriazine derivative prepared by the method has the triazine ring structure with good thermal stability, the N-Si-B elements with synergistic flame-retardant effect, good heat resistance and flame-retardant effect of the rubber compound, the quaternary ammonium salt ions with antibacterial activity providing the precursor for the combination with bacteria, the polysaccharide molecules on the surface of the bacteria, the boronic acid for the good ability of the rubber compound to capture the bacteria through the chemical bond, and the good antibacterial effect of the two. In addition, the silicon hydroxyl generated by the hydrolysis of the methoxysilane group introduced in the quaternary ammonium homotriazine derivative and the hydroxyl on the surface of the inorganic filler are subjected to dehydration condensation to prepare the modified inorganic filler, so that the dispersion uniformity of the inorganic filler in the rubber compound is improved, and the mechanical property caused by the particle agglomeration is avoided.

[0017] The modified bismaleimide monomer containing the indane structure is synthesized by using maleic anhydride and 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindane as raw materials and adopting the p-toluene sulfonic acid method cyclization method. Then, the modified additive in the form of crosslinked polymer microspheres is prepared by using 1-methyl-4-isopropyl cyclohexene and the modified bismaleimide monomer as monomer raw materials and adopting the self-stabilizing precipitation polymerization method. The modified additive contains multiple benzene ring structures, improves the molecular rigidity, and endows the rubber compound with excellent heat resistance. The introduced asymmetric indane ring reduces the regularity of the molecular structure, is helpful to reduce the melting point, and the crosslinked polymer microsphere structure of the modified additive can endow the rubber compound with good impact resistance and low dielectric property. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0019] The preparation method of the quaternary ammonium homotriazine derivative in embodiment 1 comprises the following steps: I. 9.2g of cyanuric chloride and 100mL of toluene solvent are taken in a reactor, the reaction temperature is maintained at 0℃, then 7.6g of 3,5-diaminophenyl boronic acid and 10mL of toluene are slowly added to the mixture and stirred for 5h, 5.1g of triethylamine is added in batches during the reaction, after the reaction is completed, the product is washed to neutral, the organic layer is dried with anhydrous sodium sulfate, and then concentrated to prepare a homotriazine monosubstituted body; II. Under nitrogen protection, 11.9 g of the mono-substituted s-triazine and 120 mL of N,N-dimethylformamide were taken into a reactor, 8.1 g of 3-chloropropyl trimethoxysilane and 4 g of triethylamine were added, and the mixture was stirred at 60°C for 6 h. After the reaction solution was cooled to room temperature, it was slowly poured into vigorously stirred ice water, and the organic phase was extracted, washed, dried, rotary evaporated, and column chromatographed to prepare the s-triazine intermediate. III. 0.9 g of 1,4-butanediamine and 20 mL of acetone were taken into a reactor, and after being stirred uniformly, 10.2 g of the s-triazine intermediate and 50 mL of acetone were slowly added dropwise. The reaction temperature was maintained at 35°C, and the pH value of the reaction system was adjusted to 7 using 1 mol / L sodium hydroxide aqueous solution. The reaction was continued for 4 h. After the reaction was completed, the product was prepared by filtration, washing, and drying. IV. 9.3 g of the s-triazine derivative was added to 12.2 g of N,N-dimethyl-1,3-diaminopropane in small amounts for several times, and the reaction temperature was controlled at 102°C. The reaction was stirred for 5 h. After the reaction solution was cooled to room temperature, it was dissolved in 50 mL of toluene and washed with saturated sodium chloride aqueous solution. The organic layer was dried with anhydrous sodium sulfate, filtered, and rotary evaporated to prepare the modified s-triazine derivative. V. 2.7 g of bromoethane was added to 10.7 g of the modified s-triazine derivative and 40 mL of acetone, and the mixture was heated to 60°C and stirred for 5 h. After the reaction was completed, the product was prepared by rotary evaporation under reduced pressure, recrystallization with ethyl acetate, and drying.

[0020] Example 2 A method for preparing a modified silica powder includes the following steps: 5 g of silica powder was ultrasonically dispersed in 90 mL of anhydrous ethanol and 20 mL of deionized water, and then 4.4 g of the quaternary ammonium s-triazine derivative prepared in Example 1 was added. The mixture was stirred at 65°C for 10 h. After the reaction was completed, the product was prepared by filtration, washing, and drying.

[0021] Example 3 A method for preparing a modified additive includes the following steps: ① 2.1 g of maleic anhydride, 20 mL of N,N-dimethylacetamide, and 10 mL of toluene were taken into a reactor. After the maleic anhydride was completely dissolved, 2.8 g of 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindan and 20 mL of N,N-dimethylacetamide were added dropwise. The mixture was incubated at room temperature for 3 h, and then 0.05 g of p-toluenesulfonic acid was added. The mixture was heated to 112°C and incubated for 5 h. Subsequently, the mixture was added to 50 mL of 5% sodium bicarbonate boiling water. The product was extracted with ethyl acetate, washed until neutral, rotary evaporated to remove the solvent, and dried to prepare the modified bismaleimide monomer. ②Take 0.69g modified bismaleimide monomer and 7.5mL cyclohexanone in the reactor, after stirring and dissolving, add 7.5mL n-nonyl, 0.44g 1-methyl-4-isopropyl cyclohexene and 0.027g initiator dicumyl peroxide, purge with nitrogen for 30min to remove oxygen, then react at 130℃ for 6h, after the reaction is completed, wash away the unreacted substance, and replace the solvent with methyl tert-butyl ether, then vacuum dry to prepare the modified additive.

[0022] Example 4 A modified epoxy resin potting adhesive, comprising the following components by weight: epoxy resin E51 73 parts, modified silica powder prepared in Example 2 10.8 parts, modified additive prepared in Example 3 2.1 parts, curing agent methyl hexahydrophthalic anhydride 22 parts, curing accelerator 1,8-diazabicyclo[5.4.0]undec-7-ene 1.1 parts, diluent ethylene glycol diglycidyl ether 17 parts.

[0023] The preparation method of the modified epoxy resin potting adhesive described above comprises the following steps: S1, weigh each component by weight, mix the epoxy resin and the modified additive, and then preheat at 130℃ for 50min to prepare a premix; S2, cool the system to 80℃, add modified silica powder, curing agent, curing accelerator and diluent to the premix and stir uniformly to prepare a mixture; S3, transfer the mixture to a grinder for grinding and dispersion, then deaerate in a vacuum environment for 30min, and then pour into a mold for high-temperature curing to prepare the modified epoxy resin potting adhesive.

[0024] Example 5 A modified epoxy resin potting adhesive, comprising the following components by weight: epoxy resin E51 81 parts, modified silica powder prepared in Example 2 15.5 parts, modified additive prepared in Example 3 3.3 parts, curing agent methyl hexahydrophthalic anhydride 31 parts, curing accelerator 1,8-diazabicyclo[5.4.0]undec-7-ene 1.7 parts, diluent ethylene glycol diglycidyl ether 23 parts.

[0025] The preparation method of the modified epoxy resin potting adhesive described above is the same as that of Example 4.

[0026] Example 6 A modified epoxy resin potting adhesive, comprising the following components by weight: epoxy resin E51 93 parts, modified silica powder prepared in Example 2 19.1 parts, modified additive prepared in Example 3 5.5 parts, curing agent methyl hexahydrophthalic anhydride 38 parts, curing accelerator 1,8-diazabicyclo[5.4.0]undec-7-ene 2.4 parts, diluent ethylene glycol diglycidyl ether 27 parts.

[0027] The preparation method of the modified epoxy resin potting adhesive described above is the same as that of Example 4.

[0028] Comparative Example 1 A method for preparing a modified silica powder includes the following steps: 5 g of silica powder is ultrasonically dispersed in 90 mL of anhydrous ethanol and 20 mL of deionized water, then 4.4 g of the s-triazine derivative prepared in Example 1 is added, and the mixture is stirred at 65°C for 10 h. After the reaction is completed, the modified silica powder is prepared by filtration, washing, and drying.

[0029] Comparative Example 2 A modified epoxy resin potting adhesive includes the following components by weight: 93 parts of epoxy resin E51, 19.1 parts of the modified silica powder prepared in Comparative Example 1, 5.5 parts of the modified additive prepared in Example 3, 38 parts of a curing agent methyl hexahydrophthalic anhydride, 2.4 parts of a curing accelerator 1,8-diazabicyclo[5.4.0]undec-7-ene, and 27 parts of a diluent ethylene glycol diglycidyl ether.

[0030] The preparation method of the modified epoxy resin potting adhesive described above is the same as that of Example 4.

[0031] Comparative Example 3 A modified epoxy resin potting adhesive includes the following components by weight: 93 parts of epoxy resin E51, 19.1 parts of silica powder, 5.5 parts of the modified additive prepared in Example 3, 38 parts of a curing agent methyl hexahydrophthalic anhydride, 2.4 parts of a curing accelerator 1,8-diazabicyclo[5.4.0]undec-7-ene, and 27 parts of a diluent ethylene glycol diglycidyl ether.

[0032] The preparation method of the modified epoxy resin potting adhesive described above is the same as that of Example 4.

[0033] Comparative Example 4 A modified epoxy resin potting adhesive includes the following components by weight: 93 parts of epoxy resin E51, 19.1 parts of the modified silica powder prepared in Example 2, 5.5 parts of the modified bismaleimide monomer prepared in Example 3, 38 parts of a curing agent methyl hexahydrophthalic anhydride, 2.4 parts of a curing accelerator 1,8-diazabicyclo[5.4.0]undec-7-ene, and 27 parts of a diluent ethylene glycol diglycidyl ether.

[0034] The preparation method of the modified epoxy resin potting adhesive described above is the same as that of Example 4.

[0035] Comparative Example 5 A modified epoxy resin potting adhesive includes the following components by weight: 93 parts of epoxy resin E51, 19.1 parts of the modified silica powder prepared in Example 2, 38 parts of a curing agent methyl hexahydrophthalic anhydride, 2.4 parts of a curing accelerator 1,8-diazabicyclo[5.4.0]undec-7-ene, and 27 parts of a diluent ethylene glycol diglycidyl ether.

[0036] The preparation method of the modified epoxy resin potting adhesive described above is the same as that of Example 4.

[0037] Performance detection The modified epoxy resin potting sealant prepared in Examples 4-6 and Comparative Examples 2-5 was subjected to performance testing: (1) Tensile property test: According to GB / T 2567-2021, 160 mm x 10 mm x 4 mm sealant samples were prepared, and the tensile properties of the samples were tested at a temperature of 25°C and a tensile rate of 5 mm / min. The data results are shown in Table 1.

[0038] (2) Impact resistance test: According to GB / T 6328-2021, 25 mm x 25 mm x 3 mm sealant samples were prepared for impact strength testing. The data results are shown in Table 1.

[0039] (3) Heat resistance test: 5-10 mg of sample was weighed into a ceramic crucible, and a thermal gravimetric analyzer was used to measure the thermal decomposition (TGA) curve. The N2 flow rate was 50 mL / min, the temperature range was 50-800°C, and the temperature rise rate was 20°C / min. The initial thermal decomposition temperature was used to evaluate the heat resistance of the sample. The data results are shown in Table 1.

[0040] (4) Limiting oxygen index test: 80 mm x 10 mm x 4 mm sealant samples were prepared for limiting oxygen index testing. The sample was placed in a limiting oxygen index tester, the top end of the sample was ignited, and the lowest oxygen concentration required for the sample to burn completely from top to bottom was recorded. The data results are shown in Table 1.

[0041] (5) Dielectric property test: 20 mm x 20 mm x 2 mm sealant samples were prepared for dielectric property testing. The test frequency was 100 MHz, and the test temperature was 25°C. The data results are shown in Table 1.

[0042] (6) Antibacterial property test: According to QB / T 2591-2003, the inhibition rate test was performed using Staphylococcus aureus as the test bacteria. The data results are shown in Table 1.

[0043] Table 1: Sample performance test results From the data results in Table 1, it can be seen that the potting adhesive prepared in Examples 4-6 has high tensile strength, good impact resistance, and good heat resistance, flame retardance, dielectric property and antibacterial property. The modified silica powder added in Comparative Example 2 is not quaternized with the triazine derivative, and the silica powder in Comparative Example 3 is not modified. The measured antibacterial rate of Comparative Examples 2-3 is lower than that of Examples 4-6, and the measured antibacterial rate of Comparative Example 3 is lower than that of Comparative Example 2, which shows that the quaternary ammonium salt ion and the boronic acid structural unit synergistically play a better antibacterial role. In addition, the measured tensile strength, impact strength and limiting oxygen index of Comparative Example 3 are lower than those of Examples 4-6, which is because the mechanical properties are reduced due to the agglomeration of the powder particles, and the heat resistance and flame retardance are reduced due to the lack of triazine ring structure with good thermal stability and synergistic flame retardant N-Si-B elements. In Comparative Example 4, the modified additive is replaced with an equal amount of modified bismaleimide monomer, and in Comparative Example 5, no modified additive is added. The measured impact strength of Comparative Examples 4-5 is significantly lower than that of Examples 4-6, and the dielectric constant and dielectric loss are larger than those of Examples 4-6, which shows that the addition of the modified additive is beneficial to improving the impact resistance and dielectric property of the potting adhesive. The initial thermal decomposition temperature of Comparative Example 5 is significantly lower than that of Examples 4-6, which shows that the modified bismaleimide monomer greatly improves the heat resistance of the potting adhesive to a certain extent.

[0044] In the description of the present specification, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0045] The basic principles, main features and advantages of the present application are shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A modified epoxy resin potting compound, characterized by, The composition comprises the following components in parts by weight: 70-95 parts of epoxy resin, 10-20 parts of modified inorganic filler, 2-6 parts of modified additive, 20-40 parts of curing agent, 1-3 parts of curing accelerator, and 15-30 parts of diluent. The modified inorganic filler is prepared by grafting quaternary ammonium s-triazine derivative onto the surface of inorganic filler through chemical reaction; the quaternary ammonium s-triazine derivative is prepared by substituting reaction of 3,5-diaminophenyl boronic acid with cyanuric chloride, then substituting reaction of 3-chloropropyl trimethoxysilane, preparation of s-triazine intermediate, then substituting reaction of s-triazine intermediate with 1,4-butanediamine as bridging agent, preparation of s-triazine derivative, then substituting reaction of s-triazine derivative with N,N-dimethyl-1,3-diaminopropane and quaternary ammonium treatment with bromoethane; The modified additive is prepared by using maleic anhydride and 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindane as raw materials, using p-toluenesulfonic acid method to prepare modified bismaleimide monomer, then using 1-methyl-4-isopropyl cyclohexene and modified bismaleimide monomer as monomer raw materials, using self-stabilizing precipitation polymerization method to prepare polymer.

2. The modified epoxy resin potting compound according to claim 1, characterized in that, The preparation method of the modified inorganic filler comprises the following steps: ultrasonic dispersion of inorganic filler in anhydrous ethanol and deionized water, then adding quaternary ammonium s-triazine derivative, stirring and reacting at 60-80℃ for 8-12h, and then filtering, washing and drying to prepare the modified inorganic filler. The inorganic filler is one or a combination of several of the following: silicon powder, nano-silicon dioxide, aluminum hydroxide, graphene oxide, talc powder, nano-titanium dioxide, aluminum oxide, montmorillonite and boron nitride.

3. The modified epoxy resin potting compound according to claim 2, characterized in that, The preparation method of the quaternary ammonium s-triazine derivative comprises the following steps: Ⅰ. Put cyanuric chloride and toluene solvent into a reactor, maintain the reaction temperature at-5-0℃, then slowly add a mixed solution of 3,5-diaminophenyl boronic acid and toluene, stir for 4-6h, add triethylamine in batches during the reaction, wash to neutral after the reaction is completed, dry the organic layer with anhydrous sodium sulfate, and then concentrate to prepare the s-triazine monosubstituent; Ⅱ. Under nitrogen protection, put the s-triazine monosubstituent and N,N-dimethylformamide into a reactor, add 3-chloropropyl trimethoxysilane and triethylamine, stir at 55-65℃ for 5-7h, slowly pour into vigorously stirred ice water after the reaction liquid is cooled to room temperature, extract, wash, dry, rotary evaporate, and purify by column chromatography to prepare the s-triazine intermediate; Ⅲ. Put 1,4-butanediamine and acetone solvent into a reactor, stir uniformly, then slowly drop the mixed solution of s-triazine intermediate and acetone, maintain the reaction temperature of the system at 30-35℃, adjust the pH value of the reaction system to 6-7 with sodium hydroxide solution, continue to react for 3-4h, and then filter, wash and dry to prepare the s-triazine derivative; IV. A small amount of s-triazine derivative is added to N,N-dimethyl-1,3-diaminopropane, the reaction temperature is controlled at 100-105℃, and the reaction is stirred for 4-6h. After the reaction solution is cooled to room temperature, it is dissolved in toluene and washed with saturated sodium chloride aqueous solution. The organic layer is dried with anhydrous sodium sulfate, filtered, and rotary evaporated to prepare a modified s-triazine derivative; V. Bromoethane is added to a mixed solution of the modified s-triazine derivative and acetone, heated to 55-60℃, and stirred for 4-6h. After the reaction is completed, it is concentrated under reduced pressure and recrystallized with ethyl acetate to prepare a quaternary ammonium s-triazine derivative.

4. The modified epoxy resin potting compound according to claim 3, characterized in that, In step I, the molar ratio of cyanuric chloride to 3,5-diaminophenylboronic acid is 1:1-1.

1.

5. The modified epoxy resin potting compound according to claim 3, wherein In step II, the molar ratio of s-triazine mono-substituted body to 3-chloropropyltrimethoxysilane is 1:1-1.

2.

6. The modified epoxy resin potting compound according to claim 3, wherein In step III, the molar ratio of 1,4-butanediamine to s-triazine intermediate is 1:2-2.

2.

7. The modified epoxy resin potting compound according to claim 1, wherein The preparation method of the modified additive comprises the following steps: ①Maleic anhydride, N,N-dimethylacetamide and toluene are taken in a reactor. After the maleic anhydride is completely dissolved, a mixed solution of 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindane and N,N-dimethylacetamide is added dropwise. After being kept at room temperature for 2.5-3.5h, p-toluenesulfonic acid is added, and the temperature is raised to 110-115℃. After being kept for 4.5-5.5h, boiling water containing sodium bicarbonate is added. After extraction and washing to neutral, the solvent is removed by rotary evaporation and dried to prepare a modified bismaleimide monomer; ②The modified bismaleimide monomer and cyclohexanone are taken in a reactor, stirred and dissolved, then n-nonyl, 1-methyl-4-isopropylcyclohexene and initiator dicumyl peroxide are added. After purging with nitrogen for 30min to remove oxygen, the reaction is carried out at 125-130℃ for 5.5-6h. After the reaction is completed, the unreacted substances are washed away, the solvent is replaced with methyl tert-butyl ether, and then vacuum dried to prepare a modified additive.

8. The modified epoxy resin potting compound according to claim 7, characterized in that In step ②, the addition ratio of modified bismaleimide monomer, cyclohexanone, n-nonyl, 1-methyl-4-isopropylcyclohexene and dicumyl peroxide is 0.65-0.7g:7-7.5mL:7-7.5mL:0.41-0.44g:0.025-0.03g.

9. The modified epoxy resin potting compound according to claim 1, wherein The epoxy resin is one of bisphenol A type epoxy resin, furan epoxy resin, and tetraglycidyl amine type epoxy resin; the curing agent is one or a combination of several of methylhexahydrophthalic anhydride, diamino diphenyl sulfone, phthalic anhydride, and 3-methyltetrahydrophthalic anhydride; the accelerator is one or a combination of several of 1,8-diazabicyclo[5.4.0]undec-7-ene, 2-ethyl-4-methylimidazole, tertiary amine, and dicyandiamide; and the diluent is one or a combination of several of ethylene glycol diglycidyl ether, dodecyl glycidyl ether, and neopentyl glycol diglycidyl ether.

10. The method for preparing the modified epoxy resin potting compound according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: S1, the components are weighed according to the weight parts, the epoxy resin and the modified additive are mixed, and then preheated at 125-130℃ for 40-60min to prepare a premix; S2, the system is cooled to 75~85℃, the premix is added to the modified inorganic filler, curing agent, curing accelerator, diluent stirring uniform, preparation obtained mixed material; S3, the mixed material is transferred to the grinder for grinding dispersion, then defoaming in vacuum environment for 20~60min, then poured into the mold for high temperature curing, preparation obtained modified epoxy resin pouring sealant.