An electronic grade epoxy resin composition and a method for preparing the same

Abstract

The application discloses an electronic-grade epoxy resin composition and a preparation method thereof, and belongs to the technical field of epoxy resin processing, and is used for solving the technical problem that the dielectric property and mechanical property of an electronic epoxy resin in the prior art need to be further improved. The application comprises the following raw materials in parts by weight: 30-36 parts of an epoxy resin, 35-40 parts of a modified filler, 15-20 parts of a modified toughening polyester, 5-10 parts of a curing agent, 1-2 parts of a photoinitiator and 1-6 parts of an auxiliary additive. The epoxy resin composition is obtained by taking bisphenol A type epoxy resin as a base material, taking the modified filler and the modified toughening polyester as reinforcing materials, and taking the curing agent, the photoinitiator and the auxiliary additive as additives, and is sealed and stored, so that the dielectric property, heat dissipation property and mechanical property of the electronic epoxy resin are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of epoxy resin processing, in particular to an electronic-grade epoxy resin composition and a preparation method thereof. BACKGROUND

[0002] With the rise of the fifth generation mobile communication technology, emerging technologies such as unmanned driving, wearable devices and cloud computing set new standards for signal transmission of integrated circuits. In high-speed communication circuits, microelectronic products are constantly developing towards high-density integration, high-frequency signals and high power. However, as a key substrate in microelectronic packaging, the traditional epoxy resin has been difficult to meet the development needs of high-performance circuit boards due to its relatively high dielectric constant, poor heat dissipation performance and easy aging characteristics. Therefore, it has become a hot research to prepare a high-performance electronic-grade epoxy resin composition.

[0003] The main reason for the poor dielectric performance of the traditional electronic-grade epoxy resin is that the three-dimensional network structure formed after the curing of the epoxy resin has micro-pores, which is easy to absorb moisture in a humid environment. After the water, as a polar medium, enters the interior of the material, not only the volume resistivity is reduced, but also a conductive channel is formed by ionization, further increasing the dielectric loss. In addition, the synergistic effect of the rigid benzene ring and the flexible ether bond in the molecular structure of the epoxy resin is insufficient, and the crosslinking density is too low, resulting in poor material toughness and easy molecular chain rupture at high temperature, which reduces the packaging effect of the electronic product. In addition, the humid environment easily leads to interface delamination and peeling of the packaging layer. Moreover, the molecular chain of the epoxy resin itself is mainly composed of carbon, hydrogen and oxygen elements, and has no strong thermal conductivity, resulting in low transmission efficiency of heat energy inside the resin and difficulty in dissipating the heat generated by the electronic product during work.

[0004] In view of the technical defects in this aspect, a solution is proposed. SUMMARY

[0005] The present application aims to provide an electronic-grade epoxy resin composition and a preparation method thereof, which solves the technical problem that the dielectric performance and mechanical performance of the electronic epoxy resin in the prior art need to be further improved.

[0006] The purpose of the present application can be achieved by the following technical scheme: an electronic-grade epoxy resin composition, comprising the following raw materials by weight parts: 30-36 parts of epoxy resin, 35-40 parts of modified filler, 15-20 parts of modified toughening polyester, 5-10 parts of curing agent, 1-2 parts of photoinitiator and 1-6 parts of auxiliary additive.

[0007] The modified filler is obtained by the following method:

[0008] A1, tetramethylammonium hydroxide solution, deionized water and propanol are placed in a reaction kettle, stirred for 10-15 min, γ-aminopropyl triethoxysilane is added, the temperature is raised to 40-50℃, and the reaction is kept for 4-6 h, and the modified polysiloxane is obtained after treatment;

[0009] The reaction principle for preparing the modified polysiloxane is:

[0010] During the reaction, the ethoxysilane functional group in γ-aminopropyl triethoxysilane undergoes hydrolysis reaction under the catalysis of tetramethylammonium hydroxide to generate silanol, and the silanol further undergoes condensation reaction to obtain the modified polysiloxane.

[0011] A2, deionized water, isopropanol and fluorinated nano boron nitride are placed in a reaction kettle, sodium hydroxide solution is added to adjust pH = 9 ± 0.5, modified polysiloxane is added, the temperature is raised to 40-50℃, and the reaction is kept for 3-4 h, and the modified filler is obtained after treatment.

[0012] The reaction principle for preparing the modified filler is:

[0013] During the reaction, the amino functional group of the modified polysiloxane chemically bonds with the silane coupling agent modified epoxy functional group on the surface of the fluorinated nano boron nitride to form a chemical bond, and a layer of fluorinated nano boron nitride is formed on the skeleton and surface of the modified polysiloxane to obtain the modified filler.

[0014] Further, in step A1, the concentration of the tetramethylammonium hydroxide solution is 75-80 wt%, the amount of the tetramethylammonium hydroxide solution, deionized water, propanol and γ-aminopropyl triethoxysilane is 3-5 mL: 500-620 mL: 18-20 mL: 100-110 g, and the post-treatment step includes: after the reaction is completed, the reaction system is cooled to room temperature, tetrahydrofuran is added to the reaction solution, the solid is precipitated, the filter cake is washed with deionized water for 1-2 times, and then transferred to a drying oven with a temperature of 70-80℃ for drying until the weight is constant to obtain the modified polysiloxane; in step A2, the concentration of the sodium hydroxide solution is 0.5-1.0 mol / mL, the amount of the deionized water, isopropanol, fluorinated nano boron nitride and modified polysiloxane is 15-20 mL: 15-20 mL: 1.5-2 g: 7-10 g, and the post-treatment step includes: after the reaction is completed, the filter cake is washed with deionized water and ethanol for 1-2 times, and then transferred to a drying oven with a temperature of 70-80℃ for drying until the weight is constant to obtain the modified filler.

[0015] Further, the fluorinated nano boron nitride is obtained by the following preparation method:

[0016] B1, the nano boron nitride, deionized water and ethanol are placed in a reaction kettle, heated to 40-50℃, ultrasonic 20-30min, drying, get pretreated nano boron nitride;

[0017] The reaction principle of the preparation of pretreated nano boron nitride is:

[0018] During the reaction, the high frequency vibration generated by the ultrasonic wave will exert impact force on the surface of the nano boron nitride. This mechanical vibration can decompose the organic or inorganic substances attached to the surface and remove the dirt and impurities on the surface of the particles.

[0019] B2, the pretreated nano boron nitride, ethanol and deionized water are placed in a reaction kettle, heated to 40-50℃, and γ-glycidyl ether oxygen propyl trimethoxysilane and perfluoro octyl trimethoxysilane are added, and the reaction is kept for 1-2h, and the fluorinated nano boron nitride is obtained after treatment;

[0020] The reaction principle of the fluorinated nano boron nitride is:

[0021] During the reaction, the three silicon-oxygen bonds of γ-glycidyl ether oxygen propyl trimethoxysilane and perfluoro octyl trimethoxysilane are hydrolyzed into silanol by deionized water, and the silanol further reacts with the hydroxyl groups on the surface of the nano boron nitride to obtain the silane coupling agent modified fluorinated nano boron nitride.

[0022] Further, in step B1, the amount of nano boron carbide, deionized water and ethanol is 10-15g: 50-70mL: 50-70mL, and in step B2, the amount of pretreated nano boron nitride, ethanol, deionized water, perfluoro octyl trimethoxysilane and γ-glycidyl ether oxygen propyl trimethoxysilane is 8-12g: 100-120mL: 10-15mL: 5-8g: 3-4g, and the post-treatment step includes: after the reaction is completed, suction filtration, the filter cake is washed with deionized water and ethanol for 1-2 times, and then transferred to a drying oven with a temperature of 50-60℃, dried to constant weight to obtain fluorinated nano boron nitride.

[0023] Further, the preparation method of the modified toughening polyester is: placing polyethylene glycol, dibutyltin dilaurate and tetrahydrofuran in a reaction kettle protected by nitrogen atmosphere, heating to 45-55℃, stirring for 20-30min, adding isophorone diisocyanate, and keeping the reaction for 1-2h, adding chain extender to the reaction kettle, keeping the reaction for 0.5-1h, adding end-capping agent, keeping the reaction for 1-2h, and obtaining modified toughening polyester after treatment.

[0024] The reaction formula of the modified toughening polyester is:

[0025]

[0026] In the formula:

[0027] The reaction principle for preparing the modified toughening polyester is as follows:

[0028] During the reaction, under the catalysis of dibutyltin dilaurate, nucleophilic reaction occurs between the alcohol hydroxyl group of polyethylene glycol and the isocyanate group of isophorone diisocyanate, so that an intermediate capped by isophorone diisocyanate is obtained; further nucleophilic reaction occurs between the isocyanate group of the intermediate and the alcohol hydroxyl group of the chain extender dipentaerythritol, so that the obtained product is reacted with the capping agent 2-hydroxyisopropyl methacrylate and gamma-aminopropyl triethoxysilane, so that the modified toughening polyester is obtained.

[0029] Further, the use amount ratio of the polyethylene glycol, tetrahydrofuran, dibutyltin dilaurate, chain extender and capping agent is 10-15g:200-250mL:0.5-1g:3.5-5.5g:4-6g, the chain extender is dipentaerythritol, the capping agent is composed of 2-hydroxyisopropyl methacrylate and gamma-aminopropyl triethoxysilane in a mass ratio of 2:1, the use amount of the isophorone diisocyanate is 2.1 times of the total molar amount of the hydroxyl group of the polyethylene glycol, and the post-treatment step comprises: after the reaction is completed, the temperature is raised to 70-80℃, and the pressure is reduced for distillation until no liquid is obtained, so that the modified toughening polyester prepolymer is obtained.

[0030] The application further provides a preparation method of the electronic-grade epoxy resin composition.

[0031] S1, placing the epoxy resin and auxiliary additives in a vacuum stirring and debubbling machine, uniformly mixing, vacuum debubbling, and obtaining an epoxy resin mixture;

[0032] S2, placing the curing agent, modified filler and modified toughening polyester in a vacuum stirring and debubbling machine, uniformly mixing, vacuum debubbling, and obtaining a curing agent mixture;

[0033] S3, uniformly mixing the epoxy resin mixture, photoinitiator and curing agent mixture, sealing and storing, and obtaining the epoxy resin composition.

[0034] Further, in step S1, the epoxy resin is bisphenol A type epoxy resin, the auxiliary additives are composed of diluent, antistatic agent, defoaming agent and pigment in a mass ratio of 5:2:1:2, the diluent is one or more of dibutyl phthalate, butanediol diglycidyl ether and glycidol 12-14 alkyl ether, the antistatic agent is one or both of 1-ethyl-3-methyl imidazole tetrafluoroborate and 1-butyl-3-methyl imidazole hexafluorophosphate, the defoaming agent is polydimethylsiloxane, and the pigment is one or both of phthalocyanine blue and titanium white; in step S2, the curing agent is triethylene tetramine; and in step S3, the photoinitiator is isopropyl thioxanthone.

[0035] The application has the following advantages:

[0036] 1、The electronic grade epoxy resin composition prepared by the application is prepared by using bisphenol A type epoxy resin as a base material, using modified filler and modified toughening polyester as reinforcing materials, using curing agent, photoinitiator and auxiliary additive as auxiliary agents, and sealing and storing to obtain an epoxy resin composition, which can be cured by ultraviolet light and heat to realize packaging of electronic products; the modified toughening polyester with a terminal siloxane group and a terminal olefin is prepared by using polyethylene glycol and isocyanate group as raw materials, using dipentaerythritol as a chain extender, and using 2-hydroxyisopropyl methacrylate and gamma-aminopropyl triethoxysilane as end-capping agents; the introduction of polyethylene glycol and dipentaerythritol increases the flexibility of the molecular chain, reduces the brittleness of the epoxy resin, and improves the toughness of the electronic grade epoxy resin composition; when the siloxane group of the gamma-aminopropyl triethoxysilane meets water vapor in the external environment, the siloxane bond is hydrolyzed into silanol, which can react with the polar groups such as hydroxyl groups on the surface of the modified filler and other inorganic substances, thereby improving the interfacial bonding force between the modified filler and the resin matrix; meanwhile, the hydrolysis of the siloxane bond can form a cured coating layer on the surface of the epoxy resin composition, further improving the mechanical properties of the epoxy resin composition.

[0037] 2、The electronic grade epoxy resin composition prepared by the application is prepared by washing the nano boron nitride to remove dirt, exposing more reaction sites, and then modifying the nano boron nitride with a silane coupling agent containing an epoxy group and multiple fluorine atoms to obtain fluorinated nano boron nitride; the octahedral modified polysiloxane is obtained by catalytic reaction of gamma-aminopropyl triethoxysilane; the fluorinated nano boron nitride is added to the modified polysiloxane as a skeleton, and the nucleophilic reaction occurs between the epoxy group on the surface of the fluorinated nano boron nitride and the amino group of the modified polysiloxane, obtaining a skeleton coated with fluorinated nano boron nitride on the surface; the covalent bond is formed between the epoxy group on the surface of the fluorinated nano boron nitride and the amino group of the modified polysiloxane through the nucleophilic reaction, thereby enhancing the bonding force between the fluorinated nano boron nitride and the polysiloxane skeleton; meanwhile, the introduction of fluorinated groups improves the dispersibility of the nano filler in the epoxy resin, avoiding agglomeration; the fluorinated nano boron nitride itself has high thermal conductivity and thermal stability, which can effectively disperse the heat generated by the electronic product in use, reducing local overheating; meanwhile, the fluorinated groups on the surface of the fluorinated nano boron nitride can reduce the dielectric constant of the resin composition.

[0038] 3、The electronic grade epoxy resin composition prepared by the method has a large amount of siloxane bond structure introduced by the modified filler and the modified toughening polyester, the siloxane bond has a high bond energy, the high bond energy enables the siloxane bond to remain stable at high temperatures and not easy to break, when the siloxane bond is introduced into the epoxy resin composition, the thermal stability of the epoxy resin composition can be improved, the electronic grade epoxy resin composition with a double curing mechanism is prepared by introducing the modified toughening polyester with a terminal siloxane group and a terminal olefin, under the action of a photoinitiator, the epoxy resin mixture and the curing agent mixture are subjected to photopolymerization under the action of an ultraviolet lamp, a crosslinked network is formed, and the mechanical properties of the epoxy resin composition are enhanced, after ultraviolet curing, further thermal curing is carried out, the triethylene tetramine is activated by heating, and a deep crosslinking reaction of the epoxy group and the amino group is further initiated, and the mechanical properties of the epoxy resin composition are improved, ultraviolet curing enables the surface or a thin layer to be rapidly cured and shaped, and thermal curing can penetrate to a deep layer of a complex structure, and the consistency of the overall performance of the epoxy resin composition is ensured. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be clearly and completely described below in combination with the embodiments, obviously, the described embodiments are only a 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 belong to the protection scope of the present application.

[0040] The bisphenol A type epoxy resin used in the present application is purchased from Shanghai Kaijin Chemical Co., Ltd., and the brand is 604.

[0041] Embodiment 1

[0042] The present embodiment provides a preparation method of an electronic grade epoxy resin composition, comprising the following steps:

[0043] S1, preparation of fluorinated nano boron nitride

[0044] Take: nano boron nitride 100g, deionized water 500mL and ethanol 500mL are placed in a reaction kettle, heated to 40℃, ultrasonic for 20min, dried, and the pretreated nano boron nitride is obtained;

[0045] Take: pretreated nano boron nitride 80g, ethanol 1000mL and deionized water 100mL are placed in a reaction kettle, heated to 40℃, 50g of gamma-glycidyl ether propyl trimethoxysilane and 30g of perfluorooctyl trimethoxysilane are added, and the reaction is kept for 1h, after the reaction is completed, the filter cake is washed with deionized water and ethanol for 1 time, and then transferred to a drying oven with a temperature of 50℃, and dried to constant weight to obtain fluorinated nano boron nitride.

[0046] S2, preparation of modified filler

[0047] Take: 75wt% tetramethylammonium hydroxide solution 30mL, deionized water 5000mL and propanol 180mL in the reaction kettle, stirring 10min, adding 1000g of gamma-aminopropyl triethoxysilane, heating to 40℃, keeping the reaction for 4h, after the reaction is completed, the reaction system is reduced to room temperature, add tetrahydrofuran to the reaction solution, precipitate the solid, filter, the filter cake is washed with deionized water 1 time, transfer to the drying oven with the temperature of 70℃, dry to constant weight, get the modified polysiloxane;

[0048] Take: deionized water 150mL, isopropanol 150mL and 15g of nano boron nitride fluoride, add 0.5mol / mL sodium hydroxide solution to adjust pH=9.3, add 70g of modified polysiloxane, heat to 40℃, keep the reaction for 3h, after the reaction is completed, filter, the filter cake is washed with deionized water and ethanol 1 time, transfer to the drying oven with the temperature of 70℃, dry to constant weight, get the modified filler.

[0049] S3, preparation of modified toughening polyester

[0050] Mix 2-hydroxyisopropyl methacrylate and gamma-aminopropyl triethoxysilane uniformly according to the mass ratio of 2:1 to obtain a capping agent, ready for use;

[0051] Take: 100g of polyethylene glycol, 5g of dibutyltin dilaurate and 2000mL of tetrahydrofuran in a reaction kettle protected by nitrogen atmosphere, heat to 45℃, stir for 20min, add isophorone diisocyanate according to 2.1 times of the total mole of polyethylene glycol hydroxyl, keep the reaction for 1h, add 8g of dipentaerythritol to the reaction kettle, keep the reaction for 0.5h, add 100g of capping agent, keep the reaction for 1h, after the reaction is completed, heat to 70℃, distill under reduced pressure until no liquid is collected, get the modified toughening polyester.

[0052] S4, preparation of epoxy resin composition

[0053] Mix butanediol diglycidyl ether, 1-ethyl-3-methyl imidazole tetrafluoroborate, polydimethylsiloxane and phthalocyanine blue uniformly according to the mass ratio of 5:2:1:2 to obtain an auxiliary additive, ready for use;

[0054] Take: 30 parts of bisphenol A type epoxy resin, 35 parts of modified filler, 15 parts of modified toughening polyester, 5 parts of triethylene tetramine, 1 part of isopropyl thioxanthone and 1 part of auxiliary additive, ready for use;

[0055] Put the bisphenol A type epoxy resin and auxiliary additive into a vacuum stirring degassing machine, mix uniformly, vacuum degassing, get the epoxy resin mixture;

[0056] Put triethylenetetramine, modified filler and modified toughening polyester into a vacuum stirring degassing machine, mix uniformly, vacuum degassing, to obtain a curing agent mixture;

[0057] Mix the epoxy resin mixture, isopropyl thioxanthone and the curing agent mixture uniformly, seal and store, to obtain an epoxy resin composition.

[0058] Example 2

[0059] The present embodiment provides a preparation method of an electronic-grade epoxy resin composition, comprising the following steps:

[0060] S1, preparation of fluorinated nano boron nitride

[0061] Take: 125g of nano boron nitride, 600mL of deionized water and 600mL of ethanol are placed in a reaction kettle, heated to 45℃, ultrasonic for 25min, dried, to obtain pretreated nano boron nitride;

[0062] Take: 100g of pretreated nano boron nitride, 1100mL of ethanol and 125mL of deionized water are placed in a reaction kettle, heated to 45℃, 65g of γ-glycidoxypropyltrimethoxysilane and 35g of perfluorooctyltrimethoxysilane are added, and the reaction is kept for 1.5h. After the reaction is completed, the filter cake is washed with deionized water and ethanol for 2 times, and then transferred to a drying oven with a temperature of 55℃, and dried to constant weight, to obtain fluorinated nano boron nitride.

[0063] S2, preparation of modified filler

[0064] Take: 40mL of 80wt% tetramethylammonium hydroxide solution, 5500mL of deionized water and 190mL of propanol are placed in a reaction kettle for 5h. After the reaction is completed, the reaction system is cooled to room temperature, tetrahydrofuran is added to the reaction solution, and the solid is precipitated. The filter cake is washed with deionized water for 2 times, and then transferred to a drying oven with a temperature of 75℃, and dried to constant weight, to obtain modified polysiloxane.

[0065] Take: 170mL of deionized water, 170mL of isopropyl alcohol and 17g of fluorinated nano boron nitride are placed in a reaction kettle, 1.0mol / mL sodium hydroxide solution is added to adjust pH=9.4, 85g of modified polysiloxane is added, heated to 45℃, and kept for 3.5h. After the reaction is completed, the filter cake is washed with deionized water and ethanol for 2 times, and then transferred to a drying oven with a temperature of 75℃, and dried to constant weight, to obtain a modified filler.

[0066] S3, preparation of modified toughening polyester

[0067] Mix 2-hydroxyisopropyl methacrylate and γ-aminopropyl triethoxysilane uniformly according to a mass ratio of 2:1, to obtain a capping agent, for standby use;

[0068] Take: polyethylene glycol 125g, dibutyltin dilaurate 7g and tetrahydrofuran 2250mL in a nitrogen atmosphere protection reaction kettle, heating to 50℃, stirring for 20-30min, according to the total molar amount of polyethylene glycol hydroxyl 2.1 times of isophorone diisocyanate, incubation reaction 1.5h, to the reaction kettle adding double pentaerythritol 100g, incubation reaction 1h, adding capping agent 110g, incubation reaction 1.5h, after the reaction is completed, heating to 75℃, reduced pressure distillation to no liquid, get modified toughening polyester.

[0069] S4, preparation of epoxy resin composition

[0070] Butanediol diglycidyl ether, 1-ethyl-3-methyl imidazole tetrafluoroborate, polydimethylsiloxane and phthalocyanine blue were mixed in a mass ratio of 5:2:1:2 to obtain an auxiliary additive, which was ready for use.

[0071] Take by weight: 34 parts of bisphenol A type epoxy resin, 37 parts of modified filler, 17 parts of modified toughening polyester, 7 parts of triethylene tetramine, 1.5 parts of isopropyl thioxanthone and 3 parts of auxiliary additive, ready for use;

[0072] The bisphenol A type epoxy resin and the auxiliary additive were placed in a vacuum stirring degassing machine and mixed uniformly to obtain an epoxy resin mixture.

[0073] The triethylene tetramine, modified filler and modified toughening polyester were placed in a vacuum stirring degassing machine and mixed uniformly to obtain a curing agent mixture.

[0074] The epoxy resin mixture, isopropyl thioxanthone and curing agent mixture were mixed uniformly and sealed to obtain an epoxy resin composition.

[0075] Example 3

[0076] The present embodiment provides a preparation method of an electronic grade epoxy resin composition, comprising the following steps:

[0077] S1, preparation of fluorinated nano boron nitride

[0078] Take: nano boron nitride 150g, deionized water 700mL and ethanol 700mL in a reaction kettle, heating to 50℃, ultrasonic 30min, drying, get pretreated nano boron nitride;

[0079] Weighing: 120 g of pretreated nanometer boron nitride, 1200 mL of ethanol and 150 mL of deionized water are placed in a reaction kettle, heated to 50℃, 80 g of γ-glycidyl ether propyl trimethoxysilane and 40 g of perfluoro octyl trimethoxysilane are added, and the reaction is kept for 2 h. After the reaction is completed, filter, wash the filter cake with deionized water and ethanol for 2 times, transfer to a drying oven with a temperature of 60℃, dry to constant weight, and obtain fluorinated nanometer boron nitride.

[0080] S2, preparation of modified filler

[0081] Weighing: 50 mL of 80 wt% tetramethylammonium hydroxide solution, 6200 mL of deionized water and 200 mL of propanol are placed in a reaction kettle, stirred for 150 min, 1100 g of γ-aminopropyl triethoxysilane is added, heated to 50℃, and kept for 6 h. After the reaction is completed, the reaction system is cooled to room temperature, tetrahydrofuran is added to the reaction solution, the solid is precipitated, filtered, the filter cake is washed with deionized water for 2 times, and transferred to a drying oven with a temperature of 80℃, dried to constant weight, and obtained modified polysiloxane;

[0082] Weighing: 200 mL of deionized water, 200 mL of isopropyl alcohol and 20 g of fluorinated nanometer boron nitride are placed in a reaction kettle, 1.0 mol / mL sodium hydroxide solution is added to adjust pH=9.5, 100 g of modified polysiloxane is added, heated to 50℃, and kept for h. After the reaction is completed, filter, wash the filter cake with deionized water and ethanol for 2 times, transfer to a drying oven with a temperature of 80℃, dry to constant weight, and obtain modified filler.

[0083] S3, preparation of modified toughening polyester

[0084] Mix 2-hydroxyisopropyl methacrylate and γ-aminopropyl triethoxysilane in a mass ratio of 2:1 to obtain a capping agent, which is ready for use;

[0085] Weighing: 150 g of polyethylene glycol, 10 g of dibutyltin dilaurate and 2500 mL of tetrahydrofuran are placed in a reaction kettle protected by nitrogen atmosphere, heated to 55℃, stirred for 30 min, 2.1 times of isophorone diisocyanate based on the total mole of polyethylene glycol hydroxyl is added, kept for 2 h, 120 g of dipentaerythritol is added to the reaction kettle, kept for 1 h, 120 g of capping agent is added, kept for 2 h, and the reaction is completed. After heating to 80℃, distill under reduced pressure until no liquid is collected, and obtain modified toughening polyester.

[0086] S4, preparation of epoxy resin composition

[0087] Mix butanediol diglycidyl ether, 1-ethyl-3-methyl imidazole tetrafluoroborate, polydimethylsiloxane and phthalocyanine blue in a mass ratio of 5:2:1:2 to obtain an auxiliary additive, which is ready for use;

[0088] Take by weight: 36 parts of bisphenol A type epoxy resin, 40 parts of modified filler, 20 parts of modified toughening polyester, 10 parts of triethylene tetramine, 2 parts of isopropyl thioxanthone and 6 parts of auxiliary additive, standby;

[0089] Put the bisphenol A type epoxy resin and auxiliary additive into the vacuum stirring degassing machine, mix uniformly, vacuum degassing, get the epoxy resin mixture;

[0090] Put triethylene tetramine, modified filler and modified toughening polyester into the vacuum stirring degassing machine, mix uniformly, vacuum degassing, get the curing agent mixture;

[0091] Mix the epoxy resin mixture, isopropyl thioxanthone and curing agent mixture uniformly, seal and store, get the epoxy resin composition.

[0092] Comparative example 1

[0093] The difference between this comparative example and example 2 is that the step of preparing fluorinated nano boron nitride in step S1 is cancelled, and the pretreated nano boron nitride is used instead of fluorinated nano boron nitride in the process of preparing modified filler in step S2.

[0094] Comparative example 2

[0095] The difference between this comparative example and example 2 is that the step of preparing modified filler in step S2 is cancelled, and no modified filler is added in the process of preparing epoxy resin composition in step S4.

[0096] Comparative example 3

[0097] The difference between this comparative example and example 2 is that no γ-aminopropyl triethoxysilane is added in the preparation of blocking agent in step S3, and 2-hydroxyisopropyl methacrylate is used instead of blocking agent in the process of preparing modified toughening polyester.

[0098] Performance test:

[0099] The dielectric constant and volume resistivity of the cured samples of the epoxy resin compositions prepared in examples 1-3 and comparative examples 1-3 are tested according to the standard GB / T 31838.1-2015 "dielectric and resistance characteristics of solid insulating materials Part 1: general";

[0100] The tensile strength and elongation at break of the cured samples of the epoxy resin compositions prepared in examples 1-3 and comparative examples 1-3 are tested according to the standard GB / T 1040.1-2006 "determination of tensile properties of plastics Part 1: general";

[0101] The thermal conductivity of the cured samples of the epoxy resin compositions prepared in Examples 1-3 and Comparative Examples 1-3 was tested according to the standard GB / T 29313-2012 "Test method of thermal conductivity of electrical insulating materials".

[0102] The linear thermal expansion coefficient of the cured samples of the epoxy resin compositions prepared in Examples 1-3 and Comparative Examples 1-3 was tested according to the standard GB / T 36800.2-2018 "Plastics - Thermomechanical analysis (TMA) - Part 2: Determination of linear thermal expansion coefficient and glass transition temperature", and the specific data are shown in Table 1.

[0103] The high temperature resistance of the cured samples of the epoxy resin compositions prepared in Examples 1-3 and Comparative Examples 1-3 was tested according to the high temperature and high humidity environment setting of the standard GB / T 32368-2015 "Test method for high temperature and high humidity aging resistance of adhesive tape", the dielectric constant and volume resistivity of the cured samples of the epoxy resin compositions prepared in Examples 1-3 and Comparative Examples 1-3 were tested according to the standard GB / T 31838.1-2015 "Dielectric and resistance properties of solid insulating materials - Part 1: General", the tensile strength and elongation at break of the cured samples of the epoxy resin compositions prepared in Examples 1-3 and Comparative Examples 1-3 were tested according to the standard GB / T 1040.1-2006 "Determination of tensile properties of plastics - Part 1: General", and the specific data are shown in Table 2.

[0104] Table 1 - Performance test data table of each sample before high temperature and high humidity treatment

[0105]

[0106]

[0107] Table 2 - Performance test data table of each sample after high temperature and high humidity treatment

[0108]

[0109] Data analysis:

[0110] Comparative analysis of the data in Tables 1 and 2 shows that the dielectric constant of the cured sample of the epoxy resin composition prepared by the present application is 3.01 F·m -1 , the volume resistivity is 2.25 x 10 13 Ω·m, the tensile strength is 87.01 MPa, the elongation at break is 15.41%, and the thermal conductivity is 2.74 W·(m·K) -1 , and the linear thermal expansion coefficient is only 0.27 W·(m·K) -1 , and each data is better than that of the comparative example.

[0111] After high temperature performance test, the dielectric constant of the sample cured by the epoxy resin composition prepared by the application is 3.15 F·m -1 , the volume resistivity is 2.14*10 13 Ω·m, the tensile strength is 86.51 MPa, and the elongation at break is 14.35%, which are all better than those of the comparative example;

[0112] Data description:

[0113] Through comparative analysis of the data of the comparative example 1 and the example 2, it can be seen that the volume resistivity, the tensile strength, the elongation at break and the thermal conductivity of the epoxy resin composition prepared by the application are reduced, and the linear thermal expansion coefficient and the dielectric constant are increased; after high temperature performance test, the dielectric constant and the volume resistivity of the sample cured by the epoxy resin composition prepared by the application are increased, and the tensile strength and the elongation at break are reduced, which shows that in the process of preparing the epoxy resin composition, by washing the nanometer boron nitride to remove dirt and expose more reaction sites, and then modifying it with a silane coupling agent containing an epoxy group and multiple fluorine atoms, fluorinated nanometer boron nitride is obtained, the introduction of fluorinated groups improves the dispersibility of the nanofiller in the epoxy resin, avoiding agglomeration, and the fluorinated nanometer boron nitride itself has high thermal conductivity and thermal stability, which can effectively disperse the heat generated by electronic products in use and reduce local overheating, and the fluorinated groups on the surface of the fluorinated nanometer boron nitride can reduce the dielectric constant of the resin composition.

[0114] Through comparative analysis of the data of the comparative example 2 and the example 2, it can be seen that the volume resistivity, the tensile strength, the elongation at break and the thermal conductivity of the epoxy resin composition prepared by the application are reduced, and the linear thermal expansion coefficient and the dielectric constant are increased; after high temperature performance test, the dielectric constant and the volume resistivity of the sample cured by the epoxy resin composition prepared by the application are increased, and the tensile strength and the elongation at break are reduced, which shows that in the process of preparing the epoxy resin composition, by catalyzing the γ-aminopropyl triethoxysilane to obtain multiple octahedral modified polysiloxanes of silane coupling agent hydrolysis condensation, and adding fluorinated nanometer boron nitride to the modified polysiloxane skeleton, the epoxy group on the surface of the fluorinated nanometer boron nitride and the amino group of the modified polysiloxane occur nucleophilic reaction to obtain a skeleton coated with fluorinated nanometer boron nitride on the surface, and the epoxy group on the surface of the fluorinated nanometer boron nitride and the amino group of the modified polysiloxane form a covalent bond through nucleophilic reaction, which enhances the bonding force between the fluorinated nanometer boron nitride and the polysiloxane skeleton.

[0115] By comparing and analyzing the data of Comparative Example 3 and Example 2, it can be known that the volume resistivity, tensile strength and elongation at break of the epoxy resin composition prepared by the present application are reduced, and the linear thermal expansion coefficient and dielectric constant are increased; after high temperature performance test, the dielectric constant and volume resistivity of the cured sample of the epoxy resin composition prepared by the present application are increased, and the tensile strength and elongation at break are reduced, which shows that in the process of preparing the epoxy resin composition, the modified toughening polyester with terminal siloxyl and terminal olefin is prepared by taking polyethylene glycol and isocyanate group as raw materials, taking dipentaerythritol as a chain extender, and taking 2-hydroxyisopropyl methacrylate and gamma-aminopropyl triethoxysilane as an end-capping agent, the introduction of polyethylene glycol and dipentaerythritol increases the flexibility of the molecular chain, reduces the brittleness of the epoxy resin, improves the impact resistance and crack resistance of the electronic grade epoxy resin composition, the siloxane group of gamma-aminopropyl triethoxysilane reacts with water vapor in the external environment to form silanol, and the silanol can react with the polar groups such as hydroxyl groups on the surface of the modified filler and other inorganic materials to improve the interfacial bonding force between the modified filler and the resin matrix, and at the same time, the siloxane bond hydrolysis can form a cured coating on the surface of the epoxy resin composition, further improving the mechanical properties of the epoxy resin composition.

[0116] The above disclosed preferred embodiments of the present application are only used to help explain the present application. The preferred embodiments do not describe all the details and do not limit the present application to the specific embodiments. Obviously, many modifications and changes can be made according to the content of the present application. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application. The present application is limited only by the claims and their full scope and equivalents.

Claims

1. An electronic-grade epoxy resin composition, characterized in that, The composition comprises the following raw materials by weight parts: 30-36 parts of epoxy resin, 35-40 parts of modified filler, 15-20 parts of modified toughening polyester, 5-10 parts of curing agent, 1-2 parts of photoinitiator and 1-6 parts of auxiliary additive; The modified filler is obtained by the following method: A1, the tetramethyl ammonium hydroxide solution, deionized water and propanol are placed in a reaction kettle, stirred for 10-15 min, γ-aminopropyl triethoxysilane is added, heated to 40-50℃, and reacted for 4-6h, and then treated to obtain modified polysiloxane; A2, deionized water, isopropanol and fluorinated nano boron nitride are placed in a reaction kettle, sodium hydroxide solution is added to adjust pH=9±0.5, modified polysiloxane is added, heated to 40-50℃, and reacted for 3-4h, and then treated to obtain modified filler; The fluorinated nano boron nitride is obtained by the following preparation method: B1, the nano boron nitride, deionized water and ethanol are placed in a reaction kettle, heated to 40-50℃, ultrasonic treated for 20-30min, dried to obtain pretreated nano boron nitride; B2, the pretreated nano boron nitride, ethanol and deionized water are placed in a reaction kettle, heated to 40-50℃, γ-glycidyl ether propyl trimethoxysilane and perfluoro octyl trimethoxysilane are added, and reacted for 1-2h, and then treated to obtain fluorinated nano boron nitride.

2. An electronic grade epoxy resin composition according to claim 1, wherein In step A1, the concentration of the tetramethyl ammonium hydroxide solution is 75-80wt%, and the amount ratio of the tetramethyl ammonium hydroxide solution, deionized water, propanol and γ-aminopropyl triethoxysilane is 3-5mL:500-620mL:18-20mL:100-110g; in step A2, the concentration of the sodium hydroxide solution is 0.5-1.0mol / L, and the amount ratio of the deionized water, isopropanol, fluorinated nano boron nitride and modified polysiloxane is 15-20mL:15-20mL:1.5-2g:7-10g.

3. An electronic grade epoxy resin composition according to claim 1, wherein In step B1, the amount ratio of the nano boron nitride, deionized water and ethanol is 10-15g:50-70mL:50-70mL, and in step B2, the amount ratio of the pretreated nano boron nitride, ethanol, deionized water, perfluoro octyl trimethoxysilane and γ-glycidyl ether propyl trimethoxysilane is 8-12g:100-120mL:10-15mL:5-8g:3-4g.

4. An electronic grade epoxy resin composition according to claim 1, wherein The preparation method of the modified toughening polyester is as follows: polyethylene glycol, dibutyltin dilaurate and tetrahydrofuran are placed in a reaction kettle protected by nitrogen atmosphere, heated to 45-55℃, stirred for 20-30min, isophorone diisocyanate is added, reacted for 1-2h, a chain extender is added to the reaction kettle, reacted for 0.5-1h, a capping agent is added, reacted for 1-2h, and then treated to obtain the modified toughening polyester.

5. An electronic grade epoxy resin composition according to claim 4, wherein The polyethylene glycol, tetrahydrofuran, dibutyltin dilaurate, chain extender and end capping agent are used in a ratio of 10-15g:200-250mL:0.5-1g:3.5-5.5g:4-6g, the chain extender is dipentaerythritol, the end capping agent is composed of 2-hydroxyisopropyl methacrylate and gamma-aminopropyl triethoxysilane in a mass ratio of 2:1, and the isophorone diisocyanate is used in an amount of 2.1 times the total moles of polyethylene glycol hydroxyl.

6. A method of preparing an electronic grade epoxy resin composition according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: S1, placing the epoxy resin and auxiliary additives in a vacuum stirring and degassing machine, mixing uniformly, vacuum degassing to obtain an epoxy resin mixture; S2, placing the curing agent, modified filler and modified toughening polyester in a vacuum stirring and degassing machine, mixing uniformly, vacuum degassing to obtain a curing agent mixture; S3, mixing the epoxy resin mixture, photoinitiator and curing agent mixture uniformly, sealing and storing to obtain an epoxy resin composition.

7. The method for preparing an electronic-grade epoxy resin composition according to claim 6, characterized in that, In step S1, the epoxy resin is a bisphenol A type epoxy resin, the auxiliary additives are composed of a diluent, an antistatic agent, a defoaming agent and a pigment in a mass ratio of 5:2:1:2, the diluent is one or more of dibutyl phthalate, butanediol diglycidyl ether and glycidol 12-14 alkyl ether, the antistatic agent is one or both of 1-ethyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate, the defoaming agent is polydimethylsiloxane, and the pigment is one or both of phthalocyanine blue and titanium dioxide; in step S2, the curing agent is triethylenetetramine; and in step S3, the photoinitiator is isopropyl thioxanthone.

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