Epoxy resin monomer and preparation method and application thereof

Abstract

The present invention relates to an epoxy resin monomer and its preparation method and application. The preparation method comprises the following steps: synthesizing hydroquinone with multiple carbon-fluorine bonds; mixing the hydroquinone with multiple carbon-fluorine bonds with epichlorohydrin and tetrabutylammonium bromide, stirring and reacting at 90±2°C for 5.5 to 6.5 hours; removing excess epichlorohydrin to obtain a first reaction mixture; adding toluene and sodium hydroxide solution to the first reaction mixture, stirring and reacting at 90±2°C for 2.5 to 3.5 hours to obtain a second reaction mixture; washing the second reaction mixture with water until it is neutral, vacuum drying, and obtaining an epoxy resin monomer. The technical problem solved by the present invention is how to provide an epoxy resin monomer that can improve the thermal conductivity of the electronic packaging glue when applied to the electronic packaging glue, while not reducing the mechanical properties, insulation properties and weather resistance of the electronic packaging glue, so as to be more suitable for practical use.

Description

Technical Field

[0001] The invention belongs to the technical field of functional materials, and in particular relates to an epoxy resin monomer and a preparation method and application thereof. Background Art

[0002] The core of contemporary electronic products is the electronic components. In order to protect the electronic components, they are generally packaged with electronic packaging materials. With the refinement, miniaturization and density of electronic components, their working heat is also increasing. Therefore, as an electronic packaging glue to protect electronic components, it is necessary not only to have high impact resistance, good waterproofness and insulation, but also to have a certain thermal conductivity, so as to provide heat dissipation effect for electronic components and prevent them from being damaged due to excessive heat accumulation.

[0003] There are many electronic packaging materials with single properties on the market, but there are fewer electronic packaging materials with multiple properties. Epoxy resins generally have high mechanical strength and good insulation, which can well protect integrated circuits from damage caused by short circuits and collisions; at the same time, most epoxy resins are thermosetting materials with low viscosity and good fluidity at room temperature, and the curing temperature is mostly below 200°C. Not only can they be easily shaped on the surface of integrated circuits, but they can also be cured and shaped at a temperature that does not damage the integrated circuits. Therefore, epoxy resin has always been one of the materials that are given priority when selecting electronic packaging materials. However, epoxy resin is not a very good thermal conductive material. In fact, since epoxy resin only has molecular covalent bonds after curing, heat can only be slowly transferred in epoxy resin by molecular vibration (also known as phonon heat transfer), and the efficiency of this heat transfer is extremely low. In most cases, epoxy resin not only cannot be used as a thermal conductive material, but it will play a good role in heat preservation. Compared with other materials, epoxy resin is more likely to cause secondary thermal damage to electronic components.

[0004] Although there are literature reports that adding thermal conductive fillers to epoxy resin materials can improve this problem, with the addition of thermal conductive fillers, the mechanical strength, water resistance and insulation of the epoxy resin will be greatly reduced. Summary of the invention

[0005] The main purpose of the present invention is to provide an epoxy resin monomer and a preparation method and application thereof. The technical problem to be solved is how to provide an epoxy resin monomer which, when applied to electronic packaging glue, can improve the thermal conductivity of the electronic packaging glue so that the electronic components can quickly dissipate heat when working, and will not reduce the mechanical properties, insulation properties and weather resistance of the electronic packaging glue, etc., and can protect the electronic components from possible damage caused by factors such as water vapor, electric current and collision. The electronic packaging glue has good comprehensive performance and low cost, and is therefore more suitable for practical use.

[0006] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. According to a method for preparing an epoxy resin monomer proposed in the present invention, the method comprises the following steps:

[0007] 1) Synthesis of hydroquinone with multiple carbon-fluorine bonds;

[0008] 2) mixing the hydroquinone having multiple carbon-fluorine bonds, epichlorohydrin and tetrabutylammonium bromide, and stirring the mixture at 90±2° C. for 5.5 to 6.5 hours; removing excess epichlorohydrin to obtain a first reaction mixture;

[0009] 3) adding toluene and sodium hydroxide solution to the first reaction mixture, stirring and reacting at 90±2° C. for 2.5 to 3.5 hours to obtain a second reaction mixture;

[0010] 4) washing the second reaction mixture with water until it becomes neutral, and drying it under vacuum to obtain epoxy resin monomer.

[0011] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0012] Preferably, in the aforementioned preparation method, the structural formula of the hydroquinone having multiple carbon-fluorine bonds is as shown in Formula 2:

[0013]

[0014] Preferably, in the aforementioned preparation method, the mass ratio of the hydroquinone having multiple carbon-fluorine bonds, epichlorohydrin and tetrabutylammonium bromide in step 2) is 30-32:90-100:1.

[0015] Preferably, in the aforementioned preparation method, the preparation of hydroquinone having multiple carbon-fluorine bonds in step 1) comprises the following steps:

[0016] 1a) Mix 2-methyl-4-heptafluoroisopropylaniline and deionized water, place in an ice-water bath, dropwise add concentrated hydrochloric acid and sodium nitrite solution, stir for 1 hour, filter, and obtain a diazotization reagent;

[0017] 1b) 1,4-p-benzoquinone and sodium bicarbonate are mixed, placed in an ice water bath, the diazotizing agent is added dropwise thereto, stirred, the temperature of the reaction solution is controlled to be ≤10°C, and the reaction is stirred at 8-10°C for 2.5-3.5 hours; the reaction solution is allowed to stand for 2.5-3.5 hours, filtered, the solid component is rinsed with deionized water, and vacuum dried to obtain p-benzoquinone having multiple carbon-fluorine bonds;

[0018] 1c) mixing the p-benzoquinone having multiple carbon-fluorine bonds, zinc powder and deionized water, heating to 90±2° C. under stirring, adding concentrated hydrochloric acid dropwise, and reflux for 1.5 to 2.5 hours;

[0019] 1d) filtering the reaction solution, cooling the filtrate, and obtaining crystals of hydroquinone having multiple carbon-fluorine bonds.

[0020] Preferably, in the aforementioned preparation method, the mass ratio of 2-methyl-4-heptafluoroisopropylaniline, deionized water, concentrated hydrochloric acid and sodium nitrite is 2.6-2.8:6.8-7:5.3-5.5:1; in terms of mass percentage, the amount of 1,4-p-benzoquinone is 7.7-7.9% of the total amount of 2-methyl-4-heptafluoroisopropylaniline, deionized water, concentrated hydrochloric acid and sodium nitrite, and the amount of sodium bicarbonate is 8.6-8.8% of the total amount of 2-methyl-4-heptafluoroisopropylaniline, deionized water, concentrated hydrochloric acid and sodium nitrite.

[0021] Preferably, in the aforementioned preparation method, the mass ratio of the p-benzoquinone having multiple carbon-fluorine bonds, zinc powder and deionized water in step 1c) is 1:0.8-0.9:6.5-7.0; in terms of mass percentage, the amount of concentrated hydrochloric acid is 50-60% of the total amount of the p-benzoquinone having multiple carbon-fluorine bonds, zinc powder and deionized water.

[0022] The purpose of the present invention and the solution of its technical problems are also achieved by the following technical solutions. According to an epoxy resin monomer proposed by the present invention, its molecular unit includes a plurality of benzene ring structures and a plurality of carbon-fluorine bond structures; the plurality of benzene ring structures are two adjacent benzene rings; the plurality of carbon-fluorine bond structures are -C3F7.

[0023] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0024] Preferably, the aforementioned epoxy resin monomer is prepared according to the aforementioned preparation method of the epoxy resin monomer.

[0025] The purpose of the present invention and the technical problems solved by the present invention are also achieved by adopting the following technical solutions: An epoxy resin-based electronic packaging adhesive proposed by the present invention includes the aforementioned epoxy resin monomer.

[0026] The purpose of the present invention and the technical problems solved therein are also achieved by the following technical solutions. According to the preparation method of an epoxy resin-based electronic packaging adhesive proposed by the present invention, the aforementioned epoxy resin monomer is mixed with 2-methylimidazole and hexagonal boron nitride nanopowder in a mass ratio of 100:1:25, and then the mixture is mixed with thionyl chloride and chloroform, and finally diluted with chloroform to obtain an epoxy resin-based electronic packaging adhesive.

[0027] By means of the above technical solution, the epoxy resin monomer and the preparation method and application thereof proposed in the present invention have at least the following advantages:

[0028] The epoxy resin monomer and its preparation method and application proposed by the present invention are as follows: 2-methyl-4-heptafluoroisopropylaniline is reacted with sodium nitrite under concentrated hydrochloric acid conditions to obtain a diazotization reagent; then, the diazotization reagent is added dropwise to 1,4-p-benzoquinone under the action of a sodium bicarbonate solution to modify it, thereby obtaining p-benzoquinone with multiple carbon-fluorine bonds; through the above process, multiple carbon-fluorine bonds (—C3F7) structures and multiple benzene ring structures (two adjacent benzene rings, biphenyl) can be introduced into p-benzoquinone; then, the p-benzoquinone with multiple carbon-fluorine bonds is used as a raw material, zinc powder is used as a reducing agent, and the p-benzoquinone with multiple carbon-fluorine bonds is reduced to a structure with multiple carbon-fluorine bonds under concentrated hydrochloric acid conditions. hydroquinone with multiple carbon-fluorine bonds; finally, under the catalytic action of tetrabutylammonium bromide, the phenolic hydroxyl groups of the hydroquinone with multiple carbon-fluorine bonds and the chlorine atoms in epichlorohydrin are dehydrochlorinated to obtain an epoxy resin monomer; during the above-mentioned reduction reaction and grafting reaction, the multiple carbon-fluorine bond (—C3F7) structure and the multiple benzene ring structure (two adjacent benzene rings, biphenyl) contained in the p-benzoquinone raw material with multiple carbon-fluorine bonds do not change, and are completely introduced into the epoxy resin monomer. Therefore, the epoxy resin monomer prepared by the technical solution of the present invention contains both a multiple benzene ring structure with good heat resistance, that is, a biphenyl structure, and a relatively large number of carbon-fluorine bond structures. On the one hand, a biphenyl structure is constructed in the epoxy resin. Since the benzene ring has a compact molecular structure and a high electron density, the performance of the multiple benzene ring structure is more prominent. By introducing it into the epoxy resin for modification, the strength and temperature resistance of the epoxy resin can be improved. Moreover, the biphenyl structure can provide more and stronger three-dimensional cross-linked structures, so that it can provide higher durability both for external impact and internal heating. On the other hand, a side chain containing multiple carbon-fluorine bonds is introduced into the biphenyl structure of the epoxy resin, so that it can effectively increase the fluorine content in the epoxy resin. Due to the introduction of the carbon-fluorine bond, the carbon-fluorine bond has a strong electronegativity, which greatly improves the water resistance and insulation of the epoxy resin of the present invention. That is, the molecular density of the carbon-fluorine bond is also high, which strengthens the structural strength of the three-dimensional network structure of the cured product, thereby greatly improving the impact resistance of the epoxy resin, so that the electronic packaging glue with it as the main component can effectively protect electronic components from various external damages such as water vapor, electric arc, and impact.As can be seen from the above, the technical solution of the present invention simultaneously introduces a plurality of benzene ring structures and a large number of carbon-fluorine bond structures with heat resistance into the molecular chain of the epoxy resin. The two can work together to increase the molecular density of the macromolecule in the epoxy resin and strengthen the structural strength of the three-dimensional network structure of the epoxy resin after curing, so that the electronic packaging glue prepared by the modified epoxy resin has good impact resistance, water resistance and insulation, and it can allow the addition of thermal conductive fillers without excessively affecting its weather resistance. Actual tests show that the electronic packaging glue with the modified epoxy resin as the main component has a thermal conductivity of 2.0-2.2 W / m·K, a water contact angle of greater than 90°, and a dielectric constant of less than 4.0. Furthermore, the electronic packaging glue with the modified epoxy resin monomer as the main component has an impact strength that is substantially equivalent to the tensile strength of the commonly used epoxy resin electronic packaging glue, and its test data is equivalent to 97%-101% of the prior art, indicating that the electronic packaging glue of the present invention has improved thermal conductivity while its weather resistance of various electronic components has not been seriously reduced.

[0029] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. DETAILED DESCRIPTION

[0030] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the following is a detailed description of an epoxy resin monomer and its preparation method and its specific implementation method, structure, characteristics and effects proposed by the present invention in combination with preferred embodiments.

[0031] The present invention provides a method for preparing an epoxy resin monomer, which comprises the following steps:

[0032] The first step is to prepare a para-benzoquinone containing multiple benzene ring structures and multiple carbon-fluorine bonds. The specific steps are as follows:

[0033] The first step is to prepare a diazotization reagent using 2-methyl-4-heptafluoroisopropylaniline, deionized water, concentrated hydrochloric acid and sodium nitrite as raw materials; wherein 2-methyl-4-heptafluoroisopropylaniline and sodium nitrite are reactants, and concentrated hydrochloric acid provides a concentrated acid environment for the reaction, so that the diazotization reaction can be carried out better; preferably, the feed mass ratio of 2-methyl-4-heptafluoroisopropylaniline, deionized water, concentrated hydrochloric acid and sodium nitrite is 2.6-2.8:6.8-7:5.3-5.5:1; firstly, 2-methyl-4-heptafluoroisopropylaniline and deionized water are mixed, placed in an ice water bath of ≤5°C, concentrated hydrochloric acid is added dropwise thereto to adjust the pH value to 3, so as to control the reaction process and the form of the reaction product; then, sodium nitrite solution is added dropwise thereto to react; preferably, the mass concentration of the sodium nitrite solution is 25-30%; stirring the reaction for 1h, filtering, and obtaining the diazotization reagent of 2-methyl-4-heptafluoroisopropylaniline.

[0034] The 2-methyl-4-heptafluoroisopropylaniline used in this step can be purchased from the market or synthesized in the laboratory. The specific steps are as follows: m-trifluoromethylbenzene, zinc powder and an appropriate amount of ethanol are sequentially added into an autoclave, fully mixed, and hydrogen is introduced to keep the pressure in the autoclave at about 0.1 MPa for 24 hours; the pressure is reduced to normal pressure and the gas atmosphere is replaced with nitrogen; the temperature is heated to 120° C. and reacted for 2 hours, and then the temperature in the autoclave is reduced to below 40° C.; the reaction solution is filtered to remove the zinc powder, and then the ethanol is removed by atmospheric distillation, and then reduced pressure distillation is performed, and a fraction of 60° C. is collected at a vacuum degree of 460 Pa to obtain colorless and transparent m-trichloromethylaniline; preferably, the hydrogen pressurization and reduction reaction are performed in two steps.

[0035] The second step is to prepare p-benzoquinone with multiple carbon-fluorine bonds using 1,4-p-benzoquinone, sodium bicarbonate and the above-mentioned diazotizing agent as raw materials; 1,4-p-benzoquinone and sodium bicarbonate are mixed and placed in an ice water bath of ≤5°C, and the diazotizing agent is added dropwise to 1,4-p-benzoquinone under the action of sodium bicarbonate solution for modification, and the temperature of the reaction solution is controlled to be ≤10°C during the whole process while the reagent is added dropwise, and the dropping speed should be slowly added, and the dropping speed is generally controlled to be 2-5 ml / min; in terms of mass percentage, the amount of 1,4-p-benzoquinone added is preferably the total amount of 2-methyl-4-heptafluoroisopropylaniline, deionized water, concentrated hydrochloric acid and sodium nitrite fed 7.7-7.9%; preferably, the amount of sodium bicarbonate added is 8.6-8.8% of the total amount of the 2-methyl-4-heptafluoroisopropylaniline, deionized water, concentrated hydrochloric acid and sodium nitrite; the mixture is stirred and reacted at 8-10°C for 2.5-3.5h; after the reaction is completed, the reaction solution is allowed to stand for 2.5-3.5h, filtered to obtain a crude product, i.e., a solid component; the solid component is rinsed with deionized water for multiple times, such as five times, and the product is taken out; it is placed in a vacuum oven and dried at 45-55°C to obtain a yellow p-benzoquinone product with multiple carbon-fluorine bonds; the structural formula of the p-benzoquinone product with multiple carbon-fluorine bonds is shown in Formula 1 below:

[0036]

[0037] Secondly, the p-benzoquinone with multiple carbon-fluorine bonds, zinc powder and concentrated hydrochloric acid are used as raw materials to prepare hydroquinone with multiple carbon-fluorine bonds; wherein the zinc powder is used as a reducing agent to reduce the p-benzoquinone with multiple carbon-fluorine bonds to hydroquinone with multiple carbon-fluorine bonds under concentrated hydrochloric acid conditions, and the structural formula of the p-benzoquinone product with multiple carbon-fluorine bonds is shown in Formula 2 below:

[0038]

[0039] The p-benzoquinone with multiple carbon-fluorine bonds, zinc powder and deionized water are mixed, heated to 90±2°C under stirring conditions, and then concentrated hydrochloric acid is added dropwise. After the bubbles disappear, the mixture is refluxed for 1.5 to 2.5 hours. Preferably, the mass ratio of the p-benzoquinone with multiple carbon-fluorine bonds, zinc powder and deionized water is 1:0.8 to 0.9:6.5 to 7.0. In terms of mass percentage, the amount of concentrated hydrochloric acid is preferably 50 to 60% of the total amount of the p-benzoquinone with multiple carbon-fluorine bonds, zinc powder and deionized water. The reaction mixture is filtered while hot. After the filtrate is cooled, the crystals of hydroquinone with multiple carbon-fluorine bonds can be obtained.

[0040] Finally, an epoxy resin monomer is prepared using hydroquinone having multiple carbon-fluorine bonds, epichlorohydrin, tetrabutylammonium bromide, toluene and sodium hydroxide solution as raw materials; wherein, before adding epichlorohydrin and tetrabutylammonium bromide to the hydroquinone having multiple carbon-fluorine bonds, the hydroquinone needs to be vacuum dried at a temperature of 110° C. to ensure the effect of the subsequent grafting reaction; the hydroquinone having multiple carbon-fluorine bonds, epichlorohydrin and tetrabutylammonium bromide are mixed, and stirred at 90±2° C. for 5.5 to 6.5 hours; excess epichlorohydrin is removed to obtain a first reaction mixture; tetrabutylammonium bromide is used as a catalyst, and under the catalytic action of tetrabutylammonium bromide, the reaction mixture is stirred at 90±2° C. for 5.5 to 6.5 hours; excess epichlorohydrin is removed to obtain a first reaction mixture; tetrabutylammonium bromide is used as a catalyst, and under the catalytic action of tetrabutylammonium bromide, the reaction mixture is stirred at 90±2° C. for 5.5 to 6.5 hours; excess epichlorohydrin is removed to obtain a first reaction mixture; and The phenolic hydroxyl groups of the hydroquinone with multiple carbon-fluorine bonds and the chlorine atoms in epichlorohydrin are dehydrochlorinated to obtain an epoxy resin monomer; preferably, the mass ratio of the hydroquinone with multiple carbon-fluorine bonds to epichlorohydrin and tetrabutylammonium bromide is 30-32:90-100:1; after the reaction is completed, toluene and sodium hydroxide solution are added to the first reaction mixture for extraction, and the mixture is stirred at 90±2°C for reaction for 2.5-3.5h to obtain a second reaction mixture; the second reaction mixture is washed with water until neutral, and vacuum dried to obtain a brown liquid, which is the epoxy resin monomer; the structural formula of the epoxy resin monomer is shown in Formula 3 below:

[0041]

[0042] The present invention also provides an epoxy resin monomer, wherein the molecular unit of the epoxy resin monomer comprises a plurality of benzene ring structures and a plurality of carbon-fluorine bond structures; the plurality of benzene ring structures are two adjacent benzene rings; and the plurality of carbon-fluorine bond structures are -C3F7.

[0043] Preferably, the epoxy resin monomer is prepared according to the aforementioned preparation method of the epoxy resin monomer.

[0044] The present invention also provides an epoxy resin-based electronic packaging adhesive, the main component of which includes the aforementioned epoxy resin monomer. The epoxy resin monomer prepared by the present invention is mixed with a thermal conductive filler to increase thermal conductivity while maintaining its impact resistance, water resistance, insulation and other properties without serious degradation.

[0045] The present invention also provides a method for preparing an epoxy resin-based electronic packaging adhesive, which comprises first mixing the aforementioned epoxy resin monomer with 2-methylimidazole and hexagonal boron nitride nanopowder in a mass ratio of 100:1:25, and then mixing the mixture with thionyl chloride and chloroform; preferably, the mixing ratio of the mixture to thionyl chloride and chloroform is 2.4-2.5:2.9-3.0:1.0; and finally diluting the mixture with chloroform to a mass solid content of 15-20%, thereby obtaining the epoxy resin-based electronic packaging adhesive of the present invention.

[0046] The present invention will be further described below in conjunction with specific embodiments, but this should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0047] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0048] Embodiment 1:

[0049] Add 70 mL of 2-methyl-4-heptafluoroisopropylaniline and 250 mL of deionized water to a three-necked flask. Place the three-necked flask in an ice-water bath at 5°C. Then drop 168 mL of concentrated hydrochloric acid into the three-necked flask. Then add 36.25 g of sodium nitrite into a 27.7 wt% solution through a dropping funnel, drop it into the mixture in the three-necked flask, stir for 1 hour, and filter to obtain a diazotizing agent.

[0050] Take another beaker, add a small amount of water, mix 45g of 1,4-p-benzoquinone and 50g of sodium bicarbonate in the beaker, and slowly drip the diazotization reagent prepared in this embodiment into the mixture in an ice water bath at a temperature of 5°C using a dropping funnel, control the dropping speed to 3.5ml / min, add while stirring, and control the temperature below 10°C to obtain a mixture; continue to stir the mixture at 8-10°C for 3h, then let it stand at room temperature for another 3 hours, filter the mixture to obtain a crude product, and rinse the crude product with deionized water five times. Take out the product, place it in a vacuum oven, and dry it at 50°C. The p-benzoquinone product can be obtained.

[0051] Mix 30g of the synthesized p-benzoquinone, 25g of zinc powder and 200mL of deionized water. Heat the mixture to 90°C under stirring, then drop 120mL of concentrated hydrochloric acid. After the addition is complete, reflux for 2h after the bubbles disappear. Filter the mixture while it is hot. After cooling the filtrate, the hydroquinone product can be obtained.

[0052] Mix 25g of hydroquinone, 65mL of epichlorohydrin, and 0.8g of tetrabutylammonium bromide. Stir for 6h at 90℃ in a three-necked flask. Cool to room temperature after the reaction and remove excess epichlorohydrin by distillation under reduced pressure. Subsequently, add 45mL of toluene and 30mL of 30wt% sodium hydroxide solution, and heat the mixture to 90℃ for 3h. Then, wash with deionized water until neutral. The product is vacuum dried at 60℃ for 12 hours to obtain epoxy resin monomer.

[0053] Take 100g of epoxy resin monomer, add 1g of 2-methylimidazole and 25g of hexagonal boron nitride nanopowder, then mix the mixture with 92mL of thionyl chloride and 35mL of chloroform, and then dilute the mixture with chloroform to a mass solid content of 20%, and you can get epoxy resin-based electronic packaging glue.

[0054] The electronic packaging adhesive prepared in this embodiment was thermally cured at 200° C., and the thermal conductivity of the cured product was measured to be 2.1 W / m·K, the bending strength was 115 MPa, the water contact angle was 98°, and the dielectric constant was 4.4.

[0055] Embodiment 2:

[0056] Add 70 mL of 2-methyl-4-heptafluoroisopropylaniline and 240 mL of deionized water to a three-necked flask. Place the three-necked flask in an ice-water bath at 5°C. Then drop 165 mL of concentrated hydrochloric acid into the three-necked flask. Then add 35 g of sodium nitrite into a 27.7 wt% solution through a dropping funnel, drop it into the mixture in the three-necked flask, stir for 1 hour, and filter to obtain a diazotizing agent.

[0057] Take another beaker, add a small amount of water, mix 44g of 1,4-p-benzoquinone and 49g of sodium bicarbonate in the beaker, slowly drip the diazotization reagent prepared in this embodiment into the mixture with a dropping funnel in an ice water bath at a temperature of 5°C, control the dropping speed to 3.5ml / min, add while stirring, and control the temperature below 10°C to obtain a mixture; continue to stir the mixture at 8-10°C for 3h, then let it stand at room temperature for another 3 hours, filter the mixture to obtain a crude product, and rinse the crude product with deionized water five times. Take out the product, place it in a vacuum oven, and dry it at 50°C. The p-benzoquinone product can be obtained.

[0058] Mix 30g of the synthesized p-benzoquinone, 25g of zinc powder and 200mL of deionized water. Heat the mixture to 90°C under stirring, then drop 120mL of concentrated hydrochloric acid. After the addition is complete, reflux for 2h after the bubbles disappear. Filter the mixture while it is hot. After cooling the filtrate, the hydroquinone product can be obtained.

[0059] Mix 25g of hydroquinone, 68mL of epichlorohydrin, and 0.8g of tetrabutylammonium bromide. Stir for 6h at 90℃ in a three-necked flask. Cool to room temperature after the reaction and remove excess epichlorohydrin by distillation under reduced pressure. Subsequently, add 45mL of toluene and 30mL of 30wt% sodium hydroxide solution, and heat the mixture to 90℃ for 3h. Then, wash with deionized water until neutral. The product is vacuum dried at 60℃ for 12 hours to obtain epoxy resin monomer.

[0060] Take 100g of epoxy resin monomer, add 1g of 2-methylimidazole and 25g of hexagonal boron nitride nanopowder, then mix the mixture with 92mL of thionyl chloride and 35mL of chloroform, and then dilute the mixture with chloroform to a mass solid content of 20%, and you can get epoxy resin-based electronic packaging glue.

[0061] The electronic packaging adhesive prepared in this embodiment was thermally cured at 200° C., and the thermal conductivity of the cured product was measured to be 2.2 W / m·K, the bending strength was 120 MPa, the water contact angle was 92°, and the dielectric constant was 4.3.

[0062] The technical features in the claims and / or the specification of the present invention may be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and / or the specification is also within the protection scope of the present invention.

[0063] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing an epoxy resin monomer, characterized in that: It includes the following steps: 1) Synthesizing hydroquinone having multiple carbon-fluorine bonds; wherein the structural formula of the hydroquinone having multiple carbon-fluorine bonds is shown in Formula 2: The synthesized hydroquinone having multiple carbon-fluorine bonds was subjected to vacuum drying at a temperature of 110°C; 2) mixing the hydroquinone having multiple carbon-fluorine bonds, epichlorohydrin and tetrabutylammonium bromide, and reacting them at 90±2° C. with stirring for 5.5 to 6.5 hours; removing excess epichlorohydrin to obtain a first reaction mixture; the mass ratio of the hydroquinone having multiple carbon-fluorine bonds, epichlorohydrin and tetrabutylammonium bromide is 30 to 32:90 to 100:1; 3) adding toluene and sodium hydroxide solution to the first reaction mixture, stirring and reacting at 90±2° C. for 2.5 to 3.5 hours to obtain a second reaction mixture; 4) washing the second reaction mixture with water until it is neutral, and drying under vacuum to obtain an epoxy resin monomer; the structural formula of the epoxy resin monomer is shown in Formula 3:

2. The preparation method according to claim 1, characterized in that: Step 1) The preparation of hydroquinone having multiple carbon-fluorine bonds comprises the following steps: 1a) Mix 2-methyl-4-heptafluoroisopropylaniline and deionized water, place in an ice-water bath, dropwise add concentrated hydrochloric acid and sodium nitrite solution, stir for 1 hour, filter, and obtain a diazotization reagent; 1b) 1,4-p-benzoquinone and sodium bicarbonate are mixed, placed in an ice water bath, the diazotizing agent is added dropwise thereto, stirred, the temperature of the reaction solution is controlled to be ≤10°C, and the reaction is stirred at 8-10°C for 2.5-3.5 hours; the reaction solution is allowed to stand for 2.5-3.5 hours, filtered, the solid component is rinsed with deionized water, and vacuum dried to obtain p-benzoquinone having multiple carbon-fluorine bonds; 1c) mixing the p-benzoquinone having multiple carbon-fluorine bonds, zinc powder and deionized water, heating to 90±2° C. under stirring, adding concentrated hydrochloric acid dropwise, and reflux for 1.5 to 2.5 hours; 1d) filtering the reaction solution, cooling the filtrate, and obtaining crystals of hydroquinone having multiple carbon-fluorine bonds.

3. The preparation method according to claim 2, characterized in that: The feed mass ratio of 2-methyl-4-heptafluoroisopropylaniline, deionized water, concentrated hydrochloric acid and sodium nitrite is 2.6-2.8:6.8-7:5.3-5.5:1; in terms of mass percentage, the amount of 1,4-p-benzoquinone is 7.7-7.9% of the total amount of the feed of 2-methyl-4-heptafluoroisopropylaniline, deionized water, concentrated hydrochloric acid and sodium nitrite, and the amount of sodium bicarbonate is 8.6-8.8% of the total amount of the feed of 2-methyl-4-heptafluoroisopropylaniline, deionized water, concentrated hydrochloric acid and sodium nitrite.

4. The preparation method according to claim 2, characterized in that: In step 1c), the mass ratio of the p-benzoquinone having multiple carbon-fluorine bonds, zinc powder and deionized water is 1:0.8-0.9:6.5-7.0; in terms of mass percentage, the amount of concentrated hydrochloric acid is 50-60% of the total amount of the p-benzoquinone having multiple carbon-fluorine bonds, zinc powder and deionized water.

5. An epoxy resin monomer, characterized in that Its molecular unit includes multiple benzene ring structures and multiple carbon-fluorine bond structures; the multiple benzene ring structures are two adjacent benzene rings; the multiple carbon-fluorine bond structures are -C3F7; the structural formula of the epoxy resin monomer is shown in Formula 3:

6. The epoxy resin monomer according to claim 5, characterized in that The epoxy resin monomer is prepared according to the preparation method of the epoxy resin monomer according to any one of claims 1 to 4.

7. An epoxy resin-based electronic packaging adhesive, characterized in that: It comprises the epoxy resin monomer according to claim 5 or 6.

8. A method for preparing an epoxy resin-based electronic packaging adhesive, characterized in that: The epoxy resin monomer according to claim 5 or 6 is mixed with 2-methylimidazole and hexagonal boron nitride nanopowder in a mass ratio of 100:1:25, and then the mixture is mixed with thionyl chloride and chloroform, and finally diluted with chloroform to obtain epoxy resin-based electronic packaging adhesive.

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