Moisture-proof modified epoxy resin, composite material and preparation method thereof

Abstract

The present application relates to the field of epoxy resins, and specifically discloses a moisture-proof modified epoxy resin, a composite material and a preparation method thereof. The moisture-proof modified epoxy resin includes epoxy resin, silicone resin and xylene; the composite material of the moisture-proof modified epoxy resin includes silicone-modified epoxy resin, nano-alumina, polyetherimide, glass fiber and curing agent; the preparation method thereof is as follows: the silicone-modified epoxy resin, curing agent, nano-alumina, polyetherimide and glass fiber are mixed to obtain a raw material mixture; the raw material mixture is heated and extruded at 135-145°C, pressed into sheets, cooled and crushed to obtain a modified epoxy resin composite material. The moisture-proof modified epoxy resin and composite material of the present application can be used for electronic component packaging, which has the advantage of improving the moisture-proof performance of epoxy resin.

Description

Technical Field

[0001] The present invention relates to the field of epoxy resins, and more specifically, to a moisture-proof modified epoxy resin, a composite material and a preparation method thereof. Background Art

[0002] With the continuous development of science and technology, the application of electronic components is becoming more and more extensive. However, exposed electronic components are easily damaged by physical factors such as collision, vibration, friction, etc., and are easily corroded by external environmental factors such as moisture, dust, and chemicals, which can cause the performance of electronic components to deteriorate or even be damaged. In order to solve this problem, electronic components are packaged during the manufacturing process of electronic components. The main purpose of packaging is to ensure that electronic components are isolated from the external environment to ensure their normal operation.

[0003] Traditional electronic component protection methods mainly use epoxy resin as encapsulation material. Epoxy resin has good adhesion, insulation and mechanical properties, can form a strong bond with various substrate surfaces, provide reliable bonding strength, isolate the charge and current between components and the external environment, prevent short circuit and leakage problems, and provide additional mechanical protection to prevent components from being affected by impact, vibration and stress, thus extending the service life of components.

[0004] However, there are some problems with epoxy resin. First, epoxy resin easily absorbs moisture, causing damage to electrical properties, such as changes in dielectric constant and increased leakage current. Second, epoxy resin has poor heat resistance and cannot withstand high temperature environments. Epoxy resin will undergo thermal decomposition or lose its structural stability, resulting in a decrease in mechanical properties, poor insulation performance, and may cause component failure or damage. Summary of the invention

[0005] In order to improve the moisture-proof performance of epoxy resin, the present application provides a moisture-proof modified epoxy resin, a composite material and a preparation method thereof.

[0006] In the first aspect, the present application provides a moisture-proof modified epoxy resin adopting the following technical solution:

[0007] A moisture-proof modified epoxy resin, wherein the moisture-proof modified epoxy resin is an organosilicon-modified epoxy resin, and the organosilicon-modified epoxy resin comprises 5-15 parts of epoxy resin, 1-2 parts of organosilicon resin, and 10-30 parts of xylene in parts by weight.

[0008] By adopting the above technical scheme, the epoxy resin can be modified by using an organosilicon modifier to solve the problems of poor moisture absorption and heat resistance of epoxy resin. The silicon-oxygen bond structure in the organosilicon molecule has strong hydrophobicity. By introducing the organosilicon modifier, a layer of amorphous structure similar to silica gel can be formed on the surface of the epoxy resin. This structure has good moisture resistance and can reduce the contact between the epoxy resin and the air, thereby reducing the moisture absorption rate. Since the silicon-oxygen bond replaces part of the carbon-oxygen bond, the bond energy of the silicon-oxygen bond is much larger than that of the carbon-oxygen bond, so it plays a shielding role on the connected group, can resist thermal decomposition and structural instability in a high temperature environment, thereby improving the heat resistance of the epoxy resin. Due to the introduction of the organosilicon modifier, a more compact and uniform structure is formed in the epoxy resin, which can reduce the migration and accumulation of charges, thereby reducing the change of the dielectric constant and the increase of the leakage current, and improving the insulation performance of the epoxy resin. In addition, the introduction of the organosilicon molecule can form more cross-linking points and network structures in the epoxy resin, enhance the strength and rigidity of the resin, and make it have better compression, bending and impact resistance. When used as a packaging material for electronic components, it can provide good moisture-proof and heat-resistant properties, and can provide good protection, so that the electronic components can maintain a stable and safe working state for a long time.

[0009] Optionally, the epoxy resin is bisphenol A epoxy resin.

[0010] By adopting the above technical solution, bisphenol A epoxy resin has good mechanical properties, and its strength and rigidity can be further enhanced by silicone modification. After the introduction of silicone molecules, they react with bisphenol A epoxy resin to form more cross-linking points and network structures, which improve the resin's compression, bending and impact resistance. Bisphenol A epoxy resin itself has good electrical insulation properties, and the insulation properties can be further improved by silicone modification.

[0011] Optionally, the silicone is polymethylphenylsiloxane.

[0012] By adopting the above technical solution, since polymethylphenylsiloxane has good hydrophobicity, introducing it into epoxy resin can significantly improve the hygroscopic properties of epoxy resin and reduce the risk of electrical performance damage caused by moisture absorption of epoxy resin, such as changes in dielectric constant and increase in leakage current.

[0013] In the second aspect, the present application provides a moisture-proof modified epoxy resin composite material adopts the following technical scheme: a moisture-proof modified epoxy resin composite material, comprising 30-60 parts of silicone-modified epoxy resin, 1-5 parts of nano-alumina, 0.5-3 parts of polyetherimide, 4-8 parts of glass fiber and 5-10 parts of curing agent by weight.

[0014] By adopting the above technical solution, nano-alumina is added to the composite material as a filler, which has excellent thermal conductivity and insulation properties. It can increase the thermal conductivity and insulation strength of the composite material, and improve its stability and reliability in high temperature environments. After polyetherimide is compounded with modified epoxy resin, the insulation properties of epoxy resin composite materials can be improved, and current leakage and electromagnetic interference can be reduced. Secondly, polyetherimide has high thermal stability and high temperature resistance. After being compounded with modified epoxy resin, it can significantly improve the temperature resistance of the composite material, so that it can maintain stability in high temperature environments and reduce performance losses caused by thermal decomposition. Due to the hydrophobicity and low hygroscopicity of polyetherimide, after being compounded with modified epoxy resin, the moisture resistance of the composite material is further improved. The composite material shows better stability and durability in a humid environment, thereby reducing the negative impact on electrical properties and maintaining the insulation properties of the packaging material.

[0015] Optionally, the curing agent is selected from one of fluoroborate or quaternary ammonium salt.

[0016] Optionally, the glass fiber is a sheet glass fiber with a particle size of 10-50 μm.

[0017] By adopting the above technical solution, when the flaky glass fiber with a particle size of 10-50μm is added to the modified epoxy resin, the surface area of ​​the flaky fiber is large, which can play an isolating role and reduce the chance of the resin contacting with moisture in the surrounding environment. This can effectively reduce the degree of moisture absorption of the composite material and prevent moisture from penetrating into the resin system, thereby reducing the impact of the humid environment on the resin performance. In addition, the glass fiber has excellent high temperature resistance and good thermal conductivity, which can promote heat conduction and heat dissipation, help reduce heat accumulation inside the resin, and reduce the risk of thermal decomposition and structural instability.

[0018] Optionally, the glass fiber is a modified glass fiber, and the preparation method of the modified glass fiber is:

[0019] A1. Mix 9-11 parts by weight of nano-titanium dioxide and 5-7 parts of nano-silicon dioxide with 8-12 parts of coupling agent solution, and react at 60-80° C. for 4-6 hours, then wash and dry the nano-titanium dioxide and nano-silicon dioxide;

[0020] A2. Mix the dried nano titanium dioxide and nano silicon dioxide with 45-55 parts of glass fiber, and add 50-60 parts of

[0021] Anhydrous ethanol is subjected to ultrasonic treatment and then heat-cured at 230-250° C. for 30-50 min to obtain modified glass fiber.

[0022] Nano-titanium dioxide and nano-silicon dioxide are added to epoxy resin as modifiers to improve the moisture resistance of epoxy resin. This is because the surface of the nanoparticles has a large specific surface area, which can adsorb and wrap water molecules, reducing the adsorption of moisture in the environment on epoxy resin. The coverage of nano-titanium dioxide and nano-silicon dioxide on the surface of glass fiber can form a heat-insulating layer to prevent the direct impact of high temperature on epoxy resin and improve its heat resistance. In addition, the addition of nanoparticles can also increase the heat conduction path of the material, disperse and absorb part of the heat, thereby reducing the impact of heat on epoxy resin. And the coverage of nanoparticles on the surface of glass fiber increases the interfacial bonding strength and improves the adhesion between the fiber and the epoxy resin matrix, thereby improving the strength and toughness of the composite material. In addition, the addition of nanoparticles may also improve the insulation performance of the composite material and reduce the changes in dielectric constant and leakage current.

[0023] In a third aspect, the present application provides a method for preparing a composite material of moisture-proof modified epoxy resin, using the following technical solution:

[0024] A method for preparing a moisture-proof modified epoxy resin composite material comprises the following steps:

[0025] S1, mixing the organosilicon-modified epoxy resin, curing agent, nano-alumina, polyetherimide and glass fiber to obtain a raw material mixture;

[0026] S2. The raw material mixture is heated at 135-145° C., extruded, tableted, cooled and crushed to obtain a modified epoxy resin composite material.

[0027] Optionally, the preparation method of the organosilicon-modified epoxy resin is:

[0028] The epoxy resin is mixed with polymethylphenylsiloxane and xylene solvent, stirred and reacted at 140-160° C. for 20-26 hours, and then washed with water and dried to obtain the organosilicon-modified epoxy resin.

[0029] By adopting the above technical solution, a more compact three-dimensional network structure can be formed by modifying epoxy resin with silicone, thereby improving the moisture resistance and heat resistance of the composite material. This three-dimensional network structure can effectively block the transfer of water molecules and heat, so it can significantly improve the moisture resistance and heat resistance of the material. Silicone contains abundant silicon-oxygen bonds, which can provide higher bond energy, thereby improving the heat resistance of the material. In addition, the heat resistance of silicone-modified epoxy resin can also be improved by introducing heat-resistant groups, such as benzene rings. These heat-resistant groups can absorb more heat, making the material stable at high temperatures.

[0030] Optionally, the particle size of the epoxy resin composite material after crushing is ≤150 μm.

[0031] By adopting the above technical solution, particles with a particle size of ≤150μm can be better and evenly coated on the surface of electronic components to ensure that each part is evenly covered. After being heated and pressurized, a strong and airtight packaging layer is formed to enhance the packaging effect and improve the moisture resistance, heat resistance and mechanical strength of electronic components encapsulated in epoxy resin composite materials.

[0032] In summary, this application has the following beneficial effects:

[0033] 1. Since the present application adopts silicone-modified epoxy resin, a denser three-dimensional network structure can be formed, which effectively blocks the transfer of water molecules and heat, and significantly improves moisture resistance and heat resistance. The silicon-oxygen bonds in silicone provide high bond energy and enhance heat resistance, so that electronic components can maintain a stable and safe working state for a long time.

[0034] 2. In the present application, it is preferred to use organosilicon-modified epoxy resin and nano-alumina, polyetherimide and glass fiber to prepare epoxy resin composite materials, so as to further improve the moisture resistance and thermal stability of the epoxy resin packaging material.

[0035] 3. The method of the present application crushes the epoxy resin composite material so that it can be better coated on the surface of electronic components for heating and packaging treatment, thereby further improving moisture-proof and high-temperature resistance. DETAILED DESCRIPTION

[0036] The present application is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the experiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0037] Preparation Example of Silicone-Modified Epoxy Resin

[0038] Preparation Example 1

[0039] 5 kg of bisphenol A epoxy resin, 1 kg of polymethylphenylsiloxane and 10 kg of xylene solvent were mixed, stirred at 300 r / min for 10 min using a stirrer to obtain a mixed solution, and then continuously stirred at 80 r / min at 150° C., and the stirring was stopped after the reaction for 24 hours. The product obtained by the reaction was repeatedly washed 3 times with sufficient deionized water, and the washed reactant was placed in a drying oven and dried at 60° C. to obtain a silicone-modified epoxy resin.

[0040] Preparation Example 2

[0041] 15 kg of bisphenol A epoxy resin, 2 kg of polymethylphenylsiloxane and 30 kg of xylene solvent were mixed, stirred at 300 r / min for 10 min using a stirrer to obtain a mixed solution, and then continuously stirred at 80 r / min at 150° C., and the stirring was stopped after the reaction for 24 hours. The product obtained by the reaction was repeatedly washed 3 times with sufficient deionized water, and then the washed reactant was placed in a drying oven and dried at 60° C. to obtain a silicone-modified epoxy resin.

[0042] Preparation Example 3

[0043] 10 kg of bisphenol A epoxy resin, 1.5 kg of polymethylphenylsiloxane and 20 kg of xylene solvent were mixed, stirred at 300 r / min for 10 min using a stirrer to obtain a mixed solution, and then continuously stirred at 80 r / min at 150 ° C. After reacting for 24 hours, stirring was stopped. The product obtained by the reaction was repeatedly washed 3 times with sufficient deionized water, and then the washed reactant was placed in a drying oven and dried at 60 ° C to obtain a silicone-modified epoxy resin.

[0044] Preparation Example 4

[0045] 10kg of glycidylamine epoxy resin, 1.5kg of polymethylphenylsiloxane and 20kg of xylene solvent were mixed, stirred at 300r / min for 10min using a stirrer to obtain a mixed solution, and then stirred continuously at 80r / min at 150°C. After reacting for 24h, stirring was stopped, and the product obtained by the reaction was repeatedly washed 3 times with sufficient deionized water, and then the washed reactant was placed in a drying oven and dried at 60°C to obtain a silicone-modified epoxy resin.

[0046] Preparation Example 5

[0047] 10 kg of bisphenol A epoxy resin, 1.5 kg of polydimethylsiloxane and 20 kg of xylene solvent were mixed, stirred at 300 r / min for 10 min using a stirrer to obtain a mixed solution, and then continuously stirred at 80 r / min at 150 ° C. After reacting for 24 hours, stirring was stopped, and the product obtained by the reaction was repeatedly washed 3 times with sufficient deionized water, and then the washed reactant was placed in a drying oven and dried at 60 ° C to obtain a silicone-modified epoxy resin.

[0048] Preparation example of modified glass fiber

[0049] Preparation Example 6

[0050] The preparation method of modified glass fiber is:

[0051] A1. Mix 1 kg of nano-titanium dioxide and 600 g of nano-silicon dioxide with 1 kg of 3-aminopropyltriethoxysilane solution and react at 70° C. for 5 h. Take out the nano-titanium dioxide and nano-silicon dioxide, wash them with deionized water, and then put them in a drying oven to dry.

[0052] A2. Mix the dried nano-titanium dioxide and nano-silicon dioxide with 5 kg of glass fiber, add 5 kg of anhydrous ethanol, put into a heating furnace after ultrasonic treatment, and perform heat curing treatment at 240° C. for 40 minutes. After heating, cool with the furnace to obtain modified glass fiber.

[0053] Example

[0054] Example 1

[0055] A method for preparing a composite material of moisture-proof modified epoxy resin:

[0056] S1. Mix 30 kg of organosilicon-modified epoxy resin, 1 kg of nano-alumina, 0.5 kg of polyetherimide, 4 kg of glass fiber and 5 kg of fluoroborate in a container, and stir evenly with a stirrer to obtain a raw material mixture for standby use.

[0057] S2. The raw material mixture is put into an extruder, heated and extruded at 140° C., then tableted on a tablet press and cooled, and then crushed and air-selected to obtain a powdered epoxy resin composite crude product, and then the epoxy resin composite crude product is screened with an 80-mesh sieve to obtain a modified epoxy resin composite material with a particle size of less than 150 μm.

[0058] The organosilicon-modified epoxy resin is prepared according to Preparation Example 3, and the glass fiber is a sheet-shaped glass fiber with a particle size of 10-50 μm.

[0059] Example 2

[0060] A method for preparing a composite material of moisture-proof modified epoxy resin:

[0061] S1. Mix 60 kg of organosilicon-modified epoxy resin, 5 kg of nano-alumina, 3 kg of polyetherimide, 8 kg of glass fiber and 10 kg of fluoroborate in a container, and stir evenly with a stirrer to obtain a raw material mixture for standby use.

[0062] S2. The raw material mixture is put into an extruder, heated and extruded at 140° C., then tableted on a tablet press and cooled, and then crushed and air-selected to obtain a powdered epoxy resin composite crude product, and then the epoxy resin composite crude product is screened with an 80-mesh sieve to obtain a modified epoxy resin composite material with a particle size of less than 150 μm.

[0063] The organosilicon-modified epoxy resin is prepared according to Preparation Example 3, and the glass fiber is a sheet-shaped glass fiber with a particle size of 10-50 μm.

[0064] Example 3

[0065] A method for preparing a composite material of moisture-proof modified epoxy resin:

[0066] S1. Mix 45 kg of organosilicon-modified epoxy resin, 3 kg of nano-alumina, 1.5 kg of polyetherimide, 6 kg of glass fiber and 7 kg of fluoroborate in a container, and stir evenly with a stirrer to obtain a raw material mixture for standby use.

[0067] S2. The raw material mixture is put into an extruder, heated and extruded at 140° C., then tableted on a tablet press and cooled, and then crushed and air-selected to obtain a powdered epoxy resin composite crude product, and then the epoxy resin composite crude product is screened with an 80-mesh sieve to obtain a modified epoxy resin composite material with a particle size of less than 150 μm.

[0068] The organosilicon-modified epoxy resin is prepared according to Preparation Example 3, and the glass fiber is a sheet-shaped glass fiber with a particle size of 10-50 μm.

[0069] Example 4

[0070] A method for preparing a composite material of moisture-proof modified epoxy resin is different from Example 3 in that: the organosilicon-modified epoxy resin is prepared by Preparation Example 1.

[0071] Example 5

[0072] A method for preparing a composite material of moisture-proof modified epoxy resin is different from Example 3 in that: the organosilicon-modified epoxy resin is prepared by Preparation Example 2.

[0073] Example 6

[0074] A method for preparing a composite material of moisture-proof modified epoxy resin, which is different from Example 3 in that: the organosilicon-modified epoxy resin is prepared by Preparation Example 4.

[0075] Example 7

[0076] A method for preparing a composite material of moisture-proof modified epoxy resin, which is different from Example 3 in that the organosilicon-modified epoxy resin is prepared by Preparation Example 5.

[0077] Example 8

[0078] A method for preparing a moisture-proof modified epoxy resin composite material, which differs from Example 3 in that: the glass fiber is a sheet-shaped glass fiber with a particle size of 10-50 μm, and the glass fiber is prepared by Preparation Example 6.

[0079] Example 9

[0080] A method for preparing a composite material of moisture-proof modified epoxy resin, which differs from Example 3 in that a quaternary ammonium salt is used as a curing agent.

[0081] Example 10

[0082] A method for preparing a composite material of moisture-proof modified epoxy resin, which differs from Example 3 in that: glass fibers are filamentous fibers with a diameter of 10-50 μm.

[0083] Embodiment 11

[0084] A method for preparing a moisture-proof modified epoxy resin composite material, which is different from Example 3 in that: the particle size of the modified epoxy resin composite material after crushing is greater than 150 μm.

[0085] Comparative Example

[0086] Comparative Example 1

[0087] A method for preparing a moisture-proof epoxy resin composite material:

[0088] S1. Mix 45 kg of bisphenol A epoxy resin, 3 kg of nano-alumina, 1.5 kg of polyetherimide, 6 kg of glass fiber and 7 kg of fluoroborate in a container, and stir evenly with a stirrer to obtain a raw material mixture for standby use.

[0089] S2. The raw material mixture is put into an extruder, heated and extruded at 140° C., then tableted on a tablet press and cooled, and then crushed and air-selected to obtain a powdered epoxy resin composite crude product, and then the epoxy resin composite crude product is screened with an 80-mesh sieve to obtain a modified epoxy resin composite material with a particle size of less than 150 μm.

[0090] The glass fiber is a sheet glass fiber with a particle size of 10-50 μm.

[0091] Comparative Example 2

[0092] A method for preparing a composite material of moisture-proof modified epoxy resin:

[0093] S1. Mix 45 kg of organosilicon-modified epoxy resin, 3 kg of nano-alumina, 6 kg of glass fiber and 7 kg of fluoroborate in a container, and stir them evenly with a stirrer to obtain a raw material mixture for standby use.

[0094] S2. The raw material mixture is put into an extruder, heated and extruded at 140° C., then tableted on a tablet press and cooled, and then crushed and air-selected to obtain a powdered epoxy resin composite crude product, and then the epoxy resin composite crude product is screened with an 80-mesh sieve to obtain a modified epoxy resin composite material with a particle size of less than 150 μm.

[0095] The organosilicon-modified epoxy resin is prepared according to Preparation Example 3, and the glass fiber is a sheet-shaped glass fiber with a particle size of 10-50 μm.

[0096] Comparative Example 3

[0097] A method for preparing a composite material of moisture-proof modified epoxy resin:

[0098] S1. Mix 45 kg of organosilicon-modified epoxy resin, 3 kg of nano-alumina, 1.5 kg of polyetherimide and 7 kg of fluoroborate in a container, and stir evenly with a stirrer to obtain a raw material mixture for standby use.

[0099] S2. The raw material mixture is put into an extruder, heated and extruded at 140° C., then tableted on a tablet press and cooled, and then crushed and air-selected to obtain a powdered epoxy resin composite crude product, and then the epoxy resin composite crude product is screened with an 80-mesh sieve to obtain a modified epoxy resin composite material with a particle size of less than 150 μm.

[0100] Among them, the organosilicon-modified epoxy resin is prepared by Preparation Example 3.

[0101] Performance testing

[0102] Detection Methods

[0103] 26 varistors of the same model and batch were selected and divided into 13 groups. The varistors in each group and the modified epoxy resin composite materials prepared in Examples 1-10 and Comparative Examples 1-3 were placed in a mold, molded at a pressure of 25 MPa for 5 minutes, and then cured at 170°C for 45 minutes to obtain packaged varistors.

[0104] Moisture-proof test: One piece from each of the 13 groups of packaged varistors was placed in a constant temperature of 85°C and 85wt% humidity environment and loaded with 485V DC for 1000h, and the voltage change rate and leakage current were measured.

[0105] High temperature resistance test: Take one piece from each of the 13 groups of packaged varistors and place them in an oven at a constant temperature of 135°C, load 485V DC, keep it for 1000h, and measure the voltage change rate and leakage current.

[0106] Table 1 Test data statistics

[0107]

[0108]

[0109] Combining Example 3 and Comparative Example 1 and Table 1, it can be seen that since the organic silicon modified epoxy resin is not used in Comparative Example 1, but untreated bisphenol A epoxy resin is used, it can be seen from the test results that compared with Comparative Example 1, the modified epoxy resin composite material prepared in Example 3 can have excellent moisture resistance and high temperature resistance in both moisture resistance test and high temperature resistance test, and can maintain good insulation ability in the test environment. It can be shown that by modifying the epoxy resin with an organic silicon modifier, a layer of amorphous structure similar to silica gel can be formed on the surface of the epoxy resin. This structure has good moisture resistance and can reduce the contact between the epoxy resin and the air, thereby reducing the moisture absorption rate. And it can resist thermal decomposition and structural instability in a high temperature environment, thereby improving the heat resistance of the epoxy resin. Due to the introduction of the organic silicon modifier, a more compact and uniform structure is formed in the epoxy resin, which can reduce the migration and accumulation of charges, thereby reducing the change of the dielectric constant and the increase of the leakage current, and improving the insulation performance of the epoxy resin.

[0110] Combining Example 3 and Comparative Example 2 with Table 1, it can be seen that after the polyetherimide is compounded with the modified epoxy resin, the insulation performance of the epoxy resin composite material is significantly improved, and the current leakage and electromagnetic interference are reduced. The high thermal stability and high temperature resistance of the polyetherimide enable the composite material to maintain stability in a high temperature environment and reduce the performance loss caused by thermal decomposition. In addition, the hydrophobicity and low hygroscopicity of the polyetherimide enhance the moisture resistance of the composite material, so that it can still maintain stable electrical properties and insulation properties of the packaging material in a humid environment.

[0111] Combining Example 3 and Comparative Example 3 with Table 1, it can be seen that when the flaky glass fiber with a particle size of 10-50 μm is added to the modified epoxy resin, the surface area of ​​the flaky fiber is large, which can play an isolating role and reduce the chance of the resin contacting with moisture in the surrounding environment. This can effectively reduce the degree of moisture absorption of the composite material, prevent moisture from penetrating into the resin system, and thus reduce the impact of the humid environment on the resin performance. In addition, the glass fiber has excellent high temperature resistance and good thermal conductivity, which can promote the conduction and heat dissipation of heat, help reduce the heat accumulation inside the resin, and reduce the risk of thermal decomposition and structural instability.

[0112] It can be seen from Examples 1-3 and Table 1 that by adjusting the component ratio of the modified epoxy resin composite material, the moisture resistance and high temperature resistance of the composite material can be further optimized, among which the ratio of Example 3 is the best in this application.

[0113] Combining Examples 3-7 and Table 1, it can be seen that the silicone-modified epoxy resin prepared in Preparation Example 3 has the best effect, and the composite material prepared when bisphenol A epoxy resin is used as the epoxy resin and polymethylphenylsiloxane is used as the silicone has the best moisture resistance and high temperature resistance.

[0114] It can be seen from Example 3 and Example 8 and Table 1 that the moisture resistance and heat resistance of epoxy resin can be improved by adding nano titanium dioxide and nano silicon dioxide as modifiers to glass fiber. In addition, the addition of nanoparticles can also increase the heat conduction path of the material, disperse and absorb part of the heat, and reduce the impact of heat on epoxy resin. And the addition of nanoparticles may also improve the insulation performance of the composite material and reduce the change of dielectric constant and leakage current.

[0115] It can be seen from Example 3 and Examples 9-10 and Table 1 that fluoroborate is a better choice of curing agent. Compared with fibrous glass fibers, sheet glass fibers added to the composite material have a better effect. Particles with a particle size of ≤150 μm can be better and evenly coated on the surface of electronic components to ensure that each part is evenly covered, thereby enhancing the encapsulation effect and improving the moisture resistance, heat resistance and mechanical strength of electronic components encapsulated in epoxy resin composite materials.

[0116] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A composite material of moisture-proof modified epoxy resin, characterized in that: The composition comprises 30-60 parts of organosilicon-modified epoxy resin, 1-5 parts of nano-alumina, 0.5-3 parts of polyetherimide, 4-8 parts of modified glass fiber and 5-10 parts of curing agent by weight; The organosilicon-modified epoxy resin is obtained by reacting 5-15 parts of epoxy resin, 1-2 parts of organosilicon resin and 10-30 parts of xylene, in parts by weight; The preparation method of the modified glass fiber is: A1. Mix 9-11 parts by weight of nano titanium dioxide and 5-7 parts of nano silicon dioxide with 8-12 parts of coupling agent solution, and react at 60-80° C. for 4-6 hours, then wash and dry the nano titanium dioxide and nano silicon dioxide; A2. Mix the dried nano-titanium dioxide and nano-silicon dioxide with 45-55 parts of glass fiber, add 50-60 parts of anhydrous ethanol, and perform a heat curing treatment at 230-250° C. for 30-50 minutes after ultrasonic treatment to obtain modified glass fiber; the glass fiber is a flaky fiber with a particle size of 10-50 μm.

2. The moisture-proof modified epoxy resin composite material according to claim 1, characterized in that: The epoxy resin is selected from bisphenol A epoxy resin.

3. The moisture-proof modified epoxy resin composite material according to claim 1, characterized in that: The organic silicon is polymethylphenylsiloxane.

4. The moisture-proof modified epoxy resin composite material according to claim 1, characterized in that: The curing agent is selected from fluoroborate or quaternary ammonium salt.

5. A method for preparing the composite material of moisture-proof modified epoxy resin as claimed in claim 1, characterized in that: The following steps are involved: S1, mixing the organosilicon-modified epoxy resin, curing agent, nano-alumina, polyetherimide, and modified glass fiber to obtain a raw material mixture; S2. The raw material mixture is heated at 135-145° C., extruded, tableted, cooled and crushed to obtain a modified epoxy resin composite material.

6. The method for preparing the composite material of moisture-proof modified epoxy resin according to claim 5, characterized in that: The preparation method of the organosilicon-modified epoxy resin is: The epoxy resin is mixed with polymethylphenylsiloxane and xylene solvent, stirred and reacted at 140-160° C. for 20-26 hours, and then washed with water and dried to obtain the organosilicon-modified epoxy resin.

7. The method for preparing the composite material of moisture-proof modified epoxy resin according to claim 5, characterized in that: The particle size of the modified epoxy resin composite material after crushing is ≤150 μm.

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