An epoxy resin composition, a method for preparing the same, and an application thereof

Abstract

The present application belongs to the field of underfill adhesive, and particularly relates to an epoxy resin composition, a preparation method and application thereof. The epoxy resin composition contains an epoxy resin, a tri-functional epoxy compound, a toughening agent, a curing agent, and optionally toner and a coupling agent; the tri-functional epoxy compound has a structure shown in formula (1). The key of the present application is to add a tri-functional epoxy compound with a specific structure into the epoxy resin composition, the tri-functional epoxy compound has a trisoxa tetraethyleneglycol structure and a pyridine structure, and three epoxy groups, two of which are respectively connected to the carbon atoms adjacent to the nitrogen atoms of the pyridine ring, and the remaining one is connected to the trisoxa tetraethyleneglycol structure. The specific tri-functional epoxy compound has unique electronic conjugation characteristics and chemical activity, and can endow the epoxy resin composition with good toughness. Formula (1)

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of underfill adhesive, and particularly relates to an epoxy resin composition and a preparation method and application thereof. BACKGROUND

[0002] Underfill adhesive is a resin adhesive used in electronic packaging process, which penetrates micron gap through capillary action, and is mainly applied in the field of semiconductor packaging. In addition to being filled between common PCB and chip, it is also filled between flexible soft board and chip. Compared with being filled between chip and PCB, the adhesive filled between chip and flexible soft board has more difficulties in formulation design. In addition to the basic performance of conventional underfill adhesive, the adhesive also needs to have stronger adhesive strength and toughness.

[0003] The epoxy underfill adhesive usually contains epoxy resin, toughening agent, curing agent, etc. Among them, the common epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin and alicyclic epoxy resin. When the content of epoxy groups in the epoxy resin increases, it is usually more beneficial to improve the adhesive strength, but the toughness will be poor, and the toughness will decrease more obviously at high temperature. The main reason is that such epoxy underfill adhesive forms a three-dimensional network structure after curing, which will cause the limitation of molecular chain movement. The number of epoxy groups in the epoxy resin increases, the crosslinking density also increases, and the movement limitation phenomenon is more obvious. Thus, the material becomes brittle, and the internal stress generated by curing shrinkage cannot be released, which easily leads to material cracking.

[0004] Therefore, it is urgent to develop an epoxy underfill adhesive with high toughness to meet the use requirements in the field of semiconductor packaging. SUMMARY

[0005] The first object of the present application is to provide an epoxy resin composition with high toughness.

[0006] The second object of the present application is to provide a preparation method of the above-mentioned epoxy resin composition.

[0007] The third object of the present application is to provide the application of the above-mentioned epoxy resin composition as an underfill adhesive for electronic products.

[0008] The epoxy resin composition provided by the present application contains epoxy resin, tri-functional epoxy compound, toughening agent and curing agent, and optional toner and coupling agent; the mass ratio of the epoxy resin to the tri-functional epoxy compound is 100:(10-300); the tri-functional epoxy compound has the structure shown in formula (1):

[0009] Formula (1),

[0010] In formula (1), R1 and R 2 each independently is H or C1-C5 alkyl.

[0011] The preparation method of the epoxy resin composition provided by the present application comprises mixing the epoxy resin, the tri-functional epoxy compound, the toughening agent and the curing agent, and optionally the color powder and the coupling agent uniformly, to obtain the epoxy resin composition.

[0012] The key of the present application is to add the tri-functional epoxy compound with specific structure into the epoxy resin composition, the tri-functional epoxy compound has the structure of trioxa tetraethylene glycol and pyridine structure and three epoxy groups, and two epoxy groups are respectively connected to the carbon atoms adjacent to the nitrogen atoms on the pyridine ring, and the remaining one epoxy group is connected to the trioxa tetraethylene glycol structure. The specific tri-functional epoxy compound has unique electronic conjugation characteristics and chemical activity, which can endow the epoxy resin composition with good toughness.

[0013] In a preferred embodiment, the tri-functional epoxy compound is synthesized by using halogenated epoxy propane, trioxa tetraethylene glycol and 2,6-diformyl-4-hydroxypyridine as starting materials. The halogenated epoxy propane, trioxa tetraethylene glycol and 2,6-diformyl-4-hydroxypyridine all have good reactivity and good structural stability, which can ensure the full play of the reactivity and the stability of the reaction process, and is conducive to the improvement of the total yield, thereby realizing the efficient synthesis of the tri-functional epoxy compound.

[0014] In a preferred embodiment, the curing agent contains at least a cyclic anhydride compound with the structure shown in formula (1'), which can endow the epoxy resin composition with higher high-temperature bonding strength on the basis of improving the toughness of the epoxy resin composition, so that it can better meet the needs in the field of semiconductor packaging. It is speculated that the reason is that the cyclic anhydride compound has a multi-functional anhydride structure, an aromatic ring structure, and the anhydride structure is connected to the aromatic ring structure via an ether bond. The presence of the multi-functional anhydride structure can make the epoxy resin composition form a network structure, the presence of the rigid aromatic ring structure can make the formed network molecular structure have more stability, the covalent bond forming the aromatic ring structure needs a higher temperature to be broken, and the anhydride structure is connected to the aromatic ring structure via the ether bond, so that there is a strong intermolecular force between them. The strong intermolecular force can make the molecular chain difficult to move and deform under high temperature conditions, avoiding excessive relaxation and separation of the molecular chain, thereby making the epoxy resin composition able to resist higher temperature and endowing it with higher high-temperature bonding strength. DETAILED DESCRIPTION

[0015] The epoxy resin composition provided by this invention contains epoxy resin, trifunctional epoxy compound, toughening agent, curing agent, and optionally colorant and coupling agent. Specifically, the mass ratio of epoxy resin to trifunctional epoxy compound is preferably 100:(10-300), such as 100:10, 100:20, 100:50, 100:80, 100:100, 100:120, 100:150, 100:180, 100:200, 100:220, 100:250, 100:280, 100:300, or any value between them. The preferred mass ratio of epoxy resin to toughening agent is 100:(20-300), such as 100:20, 100:50, 100:80, 100:100, 100:120, 100:150, 100:180, 100:200, 100:220, 100:250, 100:280, 100:300 or any value between them. The preferred mass ratio of epoxy resin to curing agent is 100:(20-500), such as 100:20, 100:50, 100:80, 100:100, 100:120, 100:150, 100:180, 100:200, 100:220, 100:250, 100:280, 100:300, 100:320, 100:350, 100:380, 100:400, 100:420, 100:450, 100:480, 100:500, or any value between them. The preferred mass ratio of epoxy resin to colorant is 100:(0-20), such as 0, 100:1, 100:2, 100:4, 100:6, 100:8, 100:10, 100:12, 100:14, 100:16, 100:18, 100:20, or any value between them. The preferred mass ratio of epoxy resin to coupling agent is 100:(0-100), such as 0, 100:2, 100:5, 100:10, 100:13, 100:15, 100:18, 100:20, 100:50, 100:80, 100:100, or any value between them.

[0016] In a preferred embodiment, the epoxy resin content is 10-50 parts by weight, the trifunctional epoxy compound content is 5-30 parts by weight, the toughening agent content is 10-30 parts by weight, the curing agent content is 10-50 parts by weight, the colorant content is 0.5-2 parts by weight, and the coupling agent content is 1-10 parts by weight. In this combination, the components work synergistically, resulting in improved toughness and bonding strength. Specifically, the epoxy resin content can be 10, 15, 20, 25, 30, 35, 40, 45, or 50 parts by weight, or any value between them. The trifunctional epoxy compound content can be 5, 10, 15, 20, 25, or 30 parts by weight, or any value between them. The toughening agent content can be 10, 12, 15, 18, 20, 22, 25, 28, or 30 parts by weight, or any value between them. The curing agent content can be 10, 15, 20, 25, 30, 35, 40, 45, or 50 parts by weight, or any value between them. The colorant content can be 0.5, 0.8, 1, 1.2, 1.5, 1.8, or 2 parts by weight, or any value between them. The coupling agent content can be 1, 2, 4, 6, 8, or 10 parts by weight, or any value between them.

[0017] In the epoxy resin composition, the trifunctional epoxy compound has the structure shown in formula (1):

[0018] Equation (1),

[0019] In equation (1), R 1 and R 2 Each alkyl group is independently H or C1-C5, preferably H. Examples of C1-C5 alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, or neopentyl.

[0020] In a preferred embodiment, the trifunctional epoxy compound is prepared by a method comprising the following steps:

[0021] S1. Halogenated propylene oxide and tetraethylene glycol are subjected to a first substitution reaction in the presence of base I and catalyst I. The resulting intermediate I is subjected to an active group protection reaction in the presence of base II to obtain intermediate II.

[0022] S2. 2,6-Dicarboxaldehyde-4-hydroxypyridine and phosphorus ylide are subjected to a Wittig reaction. The resulting vinyl hydroxypyridine is then subjected to a second substitution reaction with intermediate II in the presence of base III and catalyst II. Subsequently, the resulting intermediate III is oxidized to obtain a product containing a trifunctional epoxy compound.

[0023] In the preparation process of the above trifunctional epoxy compounds, the halo-epoxypropane has the structure shown in formula (2):

[0024] Equation (2),

[0025] In formula (2), X is a halogen, such as fluorine, chlorine, bromine or iodine.

[0026] In the preparation of the above trifunctional epoxy compound, the triethylene glycol has the structure shown in formula (3):

[0027] Equation (3).

[0028] In the preparation of the above trifunctional epoxy compound, the 2,6-dicarboxaldehyde-4-hydroxypyridine has the structure shown in formula (4):

[0029] Equation (4),

[0030] In equation (4), R 1 and R 2 Each alkyl group is independently H or C1-C5, preferably H. Examples of C1-C5 alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, or neopentyl.

[0031] The reaction equations for the preparation of the above trifunctional epoxy compounds are as follows:

[0032] .

[0033] In the preparation process of the above trifunctional epoxy compound, in step S1, the molar ratio of the halopropylene oxide to triethylene glycol is 1:(1-1.1), such as 1:1, 1:1.01, 1:1.02, 1:1.03, 1:1.04, 1:1.05, 1:1.06, 1:1.07, 1:1.08, 1:1.09, 1:1.1 or any value between them.

[0034] In the preparation process of the above-mentioned trifunctional epoxy compound, in step S1, the molar ratio of the active group protecting agent to triethylene glycol is preferably (0.9-1.1):1, such as 0.9:1, 0.92:1, 0.94:1, 0.96:1, 0.98:1, 1:1, 1.02:1, 1.04:1, 1.06:1, 1.08:1, 1.1:1, or any value between them. The active group protecting agent may include at least one of tert-butyldimethylchlorosilane (TBSCl), trimethylchlorosilane, triethylchlorosilane, triisopropylchlorosilane, dimethylphenylchlorosilane, and tert-butyldiphenylchlorosilane.

[0035] In the preparation process of the above trifunctional epoxy compound, in step S2, the molar ratio of 2,6-dicarboxaldehyde-4-hydroxypyridine to intermediate II is preferably 1:(0.9-1.1), such as 1:0.9, 1:0.92, 1:0.94, 1:0.96, 1:0.98, 1:1, 1:1.02, 1:1.04, 1:1.06, 1:1.08, 1:1.1 or any value between them.

[0036] In the preparation process of the above trifunctional epoxy compound, in step S1, the conditions for the first substitution reaction preferably include a temperature of 50℃-70℃, such as 50℃, 52℃, 55℃, 58℃, 60℃, 62℃, 65℃, 68℃, 70℃ or any value between them; and a time of 10h-24h, such as 10h, 12h, 14h, 16h, 18h, 20h, 22h, 24h or any value between them.

[0037] In the preparation process of the above trifunctional epoxy compound, in step S1, the conditions for the active group protection reaction preferably include a temperature of 10℃-30℃, such as 10℃, 12℃, 15℃, 18℃, 20℃, 22℃, 25℃, 28℃, 30℃ or any value between them; and a time of 5h-12h, such as 5h, 8h, 10h, 12h or any value between them.

[0038] In the preparation process of the above trifunctional epoxy compound, in step S2, the Wittig reaction conditions preferably include a temperature of -20℃ to 0℃, such as -20℃, -18℃, -16℃, -14℃, -12℃, -10℃, -8℃, -6℃, -4℃, -2℃, 0℃ or any value between them; and a time of 1h to 24h, such as 1h, 2h, 4h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h, 24h or any value between them.

[0039] In the preparation process of the above trifunctional epoxy compound, in step S2, the conditions for the second substitution reaction include a temperature of 25℃-100℃, such as 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃ or any value between them; and a time of 2h-18h, such as 2h, 4h, 6h, 8h, 10h, 12h, 14h, 16h, 18h or any value between them.

[0040] In the preparation process of the above trifunctional epoxy compound, in step S2, the oxidation reaction conditions preferably include a temperature of 40℃-100℃, such as 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃ or any value between them; and a time of 6h-18h, such as 6h, 8h, 10h, 12h, 14h, 16h, 18h or any value between them.

[0041] In a preferred embodiment, in step S1, the method for the first substitution reaction and the active group protection reaction includes dissolving halopropylene oxide, base I, and catalyst I in organic solvent I, heating the resulting mixture to the first substitution reaction temperature under inert gas protection and stirring, then adding tetraethylene glycol trioxide to carry out the first substitution reaction, removing the solvent after the reaction is complete, washing the crude product with water and drying it, then dissolving the obtained intermediate I, base II, and active group protectant in organic solvent II to carry out the active group protection reaction, removing the solvent after the reaction is complete, washing the crude product with water and drying it to obtain intermediate II.

[0042] In a preferred embodiment, step S2, the method for the Wittig reaction, the second substitution reaction, and the oxidation reaction includes dissolving 2,6-dicarboxaldehyde-4-hydroxypyridine and phosphorus ylide in organic solvent III, then reacting at the Wittig reaction temperature under inert gas protection. After the reaction is complete, water is added sequentially for quenching, extraction, solvent removal, and drying to obtain vinylhydroxypyridine. Vinylhydroxypyridine, base III, and catalyst II are dissolved in organic solvent IV, and the temperature is raised to the second substitution reaction temperature under inert gas protection and stirring. Then, intermediate II is added to carry out the second substitution reaction. After the reaction is complete, the solvent is removed to obtain intermediate III. Intermediate III is dissolved in organic solvent V, cooled to -5°C to 5°C, and an oxidant is slowly added. The temperature is then raised to the oxidation reaction temperature to continue the reaction. After the reaction is complete, a product containing a trifunctional epoxy compound is obtained. The phosphorus ylide is generally generated by triphenylmethylphosphorus bromide under the action of a strong base. The strong base may include at least one of n-butyllithium, phenyllithium, potassium tert-butoxide, and sodium tert-butoxide. In the specific reaction process, 2,6-dicarboxaldehyde-4-hydroxypyridine, triphenylmethylphosphorus bromide, and the strong base can be dissolved in organic solvent III, and then the reaction is carried out under inert gas protection at the Wittig reaction temperature.

[0043] The preferred method for preparing trifunctional epoxy compounds provided by the present invention further includes purifying and separating the trifunctional epoxy compounds from the product containing the trifunctional epoxy compounds. The purification method includes adding organic solvent V to the product containing the trifunctional epoxy compounds for dilution, then washing the resulting diluted solution sequentially with saturated sodium bicarbonate aqueous solution and saturated sodium thiosulfate aqueous solution, collecting the organic phase and removing the solvent to obtain the trifunctional epoxy compounds.

[0044] In the preparation of the above-mentioned trifunctional epoxy compound, the types of base I, base II, and base III are not particularly limited and can be conventional choices in the art, as long as they can provide an alkaline environment. For example, they can each be independently selected from at least one of cesium carbonate, sodium bicarbonate, potassium carbonate, potassium hydroxide, sodium hydroxide, and lithium hydroxide. In a preferred embodiment, base I is cesium carbonate or potassium carbonate, base II is triethylamine or sodium hydroxide, and base III is selected from at least one of sodium carbonate, sodium carbonate, potassium hydroxide, and sodium hydroxide. Using the above-mentioned preferred alkaline substances in combination can more effectively promote the formation of reaction products and avoid the formation of by-products, thereby improving the product yield. In addition, the molar ratio of the sum of base I, base II, and base III to epichlorohydrin is preferably (1-5):1, such as 1:1, 1.2:1, 1.5:1, 2:1, 3:1, 3.6:1, 4:1, 4.5:1, 5:1, or any value between them.

[0045] In the preparation of the above trifunctional epoxy compounds, the types of organic solvent I, organic solvent II, organic solvent III, organic solvent IV, and organic solvent V are not particularly limited. They can be any existing inert liquid substances that can be used as reaction media, and can be at least one of alcohol solvents, ester solvents, ether solvents, hydrocarbon solvents, ketone solvents, etc. Specifically, they can be selected from at least one of acetonitrile, dichloromethane, tetrahydrofuran, and N,N-dimethylformamide.

[0046] In the preparation of the above-mentioned trifunctional epoxy compounds, the types of catalysts I and II are not particularly limited, and can be any existing substances that can improve the rate of substitution reactions. Catalyst I can include at least one of benzyltriethylammonium chloride, 18-crown ether-6, tetrabutylammonium chloride, and tetrabutylammonium bromide, with tetrabutylammonium bromide being particularly preferred. Catalyst II can include at least one of 4-dimethylaminopyridine, tetrabutylammonium hydroxide, trioctylmethylammonium chloride, 15-crown ether-5, tetradecyltrimethylammonium chloride, triphenylmethylphosphine bromide, and trioctylmethylphosphine chloride, with 15-crown ether-5 being preferred. When catalysts I and II are selected as the above-mentioned preferred catalysts, it is more beneficial to improve the yield of the trifunctional epoxy compounds.

[0047] In the preparation of the above trifunctional epoxy compounds, the terms "Ⅰ", "Ⅱ", "Ⅲ", "Ⅳ" and "Ⅴ" are merely used to distinguish the same type of substance used in different steps for ease of description, and have no other special meaning.

[0048] In the preparation of the above-mentioned trifunctional epoxy compounds, the type of oxidant is not particularly limited and can be any existing substance that can improve the reaction rate, such as at least one of potassium permanganate, manganese dioxide, potassium peroxymonosulfonate, and m-chloroperoxybenzoic acid (m-CPBA), with m-CPBA being particularly preferred. When m-CPBA is selected as the oxidant, it is more beneficial to improve the yield of the trifunctional epoxy compounds.

[0049] In the epoxy resin composition, the curing agent preferably contains at least a cyclic anhydride compound, and may be solely a cyclic anhydride compound, or a mixture of a cyclic anhydride compound and a conventional anhydride curing agent. Preferably, the cyclic anhydride compound accounts for 10-100% of the total weight of the curing agent, more preferably 20-100%, further preferably 30-100%, more preferably 40-100%, more preferably 50-100%, more preferably 60-100%, more preferably 70-100%, more preferably 80-100%, more preferably 90-100%, and most preferably 100%. A higher proportion of the cyclic anhydride compound is more beneficial for improving bond strength. The conventional anhydride curing agents may include at least one of the following: methylnadic anhydride, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, bicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, hexahydro-4-methylphthalic anhydride (MHHPA), methyltetrahydrophthalic anhydride (MTHPA), methylcyclohexene-1,2-dicarboxylic anhydride, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, bicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, (2-dodecen-1-yl)succinic anhydride, glutaric anhydride, citrate anhydride, methylsuccinic anhydride, 2,2-dimethylsuccinic anhydride, 2,2-dimethylglutaric anhydride, 3-methylglutaric anhydride, 3,3-tetramethyleneglutaric anhydride, and 3,3-dimethylglutaric anhydride.

[0050] In the epoxy resin composition, the curing agent cyclic anhydride compound has the structure shown in formula (1'):

[0051] Equation (1`),

[0052] In equation (1), R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 R 13 and R 14 Each of the alkyl groups is independently H or C1-C6. Examples of C1-C6 alkyl groups include: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, or neopentyl.

[0053] In the epoxy resin composition, the cyclic anhydride compound preferably has a symmetrical structure, in which case R1, R7, R8, and R... 14 The same applies to R2, R6, R9, and R... 13 Same, R3, R5, R 10 and R 12 Same, R4 and R 11 The same. When cyclic anhydride compounds have a symmetrical structure, the overall structure after curing can be guaranteed to be stable and not easily affected by external conditions (such as temperature changes), resulting in higher high-temperature adhesive strength. In a preferred embodiment, in formula (1'), R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 R 13 and R 14 All are H.

[0054] In a preferred embodiment, the cyclic anhydride compound is prepared by a method comprising the following steps:

[0055] S1'. Michael addition: A polyhydroxy aromatic compound is reacted with acrylonitrile via cyanoethylation to yield a polycyano aromatic compound;

[0056] S2'. Cyano hydrolysis: The polycyano aromatic compound is hydrolyzed to convert the cyano group into a carboxyl group, yielding a polycarboxyl aromatic compound;

[0057] S3`. Intramolecular condensation: Intramolecular anhydride reaction of polycarboxylic aromatic compounds to obtain cyclic anhydride compounds.

[0058] In the preparation of the above-mentioned cyclic anhydride compounds, the polyhydroxy aromatic compounds have the structure shown in formula (2'):

[0059] Equation (2'),

[0060] In equation (2'), R3, R4, R5, R 10 R11 and R 12 Each of the alkyl groups is independently H or C1-C6. Examples of C1-C6 alkyl groups include: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, or neopentyl.

[0061] In the preparation of the above-mentioned cyclic anhydride compounds, the polyhydroxy aromatic compound preferably has a symmetrical structure, in which case R3, R5, and R... 10 and R 12 Same, R4 and R 11 same.

[0062] In a preferred embodiment, in formula (2'), R3, R4, R5, R 10 R 11 and R 12 All are H.

[0063] In the preparation of the above-mentioned cyclic anhydride compounds, in step S1', the cyanoethylation reaction is carried out in the presence of a base and an organic solvent. The molar ratio of the base to the polyhydroxy aromatic compound is preferably 5:1 to 12:1, such as 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, 10:1, 10.5:1, 11:1, 11.5:1, 12:1, or any value between them. The amount of acrylonitrile used is preferably 5 to 12 times the molar amount of the polyhydroxy aromatic compound, such as 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, 11 times, 12 times, 13 times, 14 times, 15 times, or any value between them. The preferred conditions for the cyanoethylation reaction include a temperature of 20–50°C, such as 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, or any value between therewith; and a time of 8–24 h, such as 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h, or any value between therewith. The base may include at least one of potassium hydroxide, sodium hydroxide, potassium carbonate, and sodium carbonate. The organic solvent is preferably methanol and / or ethanol.

[0064] In the preparation process of the above-mentioned cyclic anhydride compounds, in step S2', the hydrolysis reaction includes reflux reaction of the polycyano aromatic compound in a concentrated hydrochloric acid / methanol system. The volume ratio of the concentrated hydrochloric acid to methanol is preferably 1:3 to 1:5, such as 1:3, 1:3.5, 1:4, 1:4.5, 1:5, or any value between them. The reflux reaction time is preferably 6h to 24h, such as 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h, 24h, or any value between them.

[0065] In the preparation of the above-mentioned cyclic anhydride compounds, in step S3', the intramolecular anhydride reaction is preferably carried out in the presence of dicyclohexylcarbodiimide (DCC). The molar ratio of the dicyclohexylcarbodiimide to the polycarboxylic aromatic compound is preferably 2:1 to 3:1, such as 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, 3:1, or any value between them. The preferred conditions for the intramolecular anhydride reaction include a temperature of 0~30℃, such as 0℃, 2℃, 5℃, 8℃, 10℃, 12℃, 15℃, 18℃, 20℃, 22℃, 25℃, 30℃ or any value between them; and a time of 10~36h, such as 10h, 12h, 14h, 16h, 18h, 20h, 22h, 24h, 26h, 28h, 30h, 32h, 34h, 36h or any value between them.

[0066] The reaction mechanism for the preparation of the above-mentioned cyclic anhydride compounds is as follows:

[0067] .

[0068] In the epoxy resin composition, the epoxy resin can be any of the existing aromatic epoxy resins and / or aliphatic epoxy resins, specific examples of which include, but are not limited to: at least one of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, o-hydroxymethyl bisphenol A diglycidyl ether, dihydroxymethyl bisphenol A diglycidyl ether, tetrabromobisphenol A diglycidyl ether, resorcinol diglycidyl ether, and pyromelliticol triglycidyl ether pentaerythritol diglycidyl ether, preferably bisphenol A diglycidyl ether and / or bisphenol F diglycidyl ether.

[0069] In the epoxy resin composition, specific examples of the toughening agent include, but are not limited to, at least one of: polyurethane, cashew nutshell liquid-modified phenolic resin, unsaturated polyester resin, epoxy resin active toughening agent, and SBS thermoplastic elastomer. The unsaturated polyester resin may be at least one of 182 unsaturated polyester resin, 196 unsaturated polyester resin, etc.

[0070] In the epoxy resin composition, the pigment can be selected according to the actual application scenario, without any particular limitation, and can be at least one of titanium dioxide, carbon black, iron oxide red, etc.

[0071] In the epoxy resin composition, the coupling agent is used to improve the compatibility between the organic and inorganic components of the epoxy resin composition and increase the adhesive strength. Examples of coupling agents include at least one selected from: γ-aminopropyltriethylsiloxane, γ-glycidoxypropyltrimethoxysiloxane, γ-methacrylate propyltrimethoxysiloxane, γ-thiol propyltrimethoxysiloxane, vinyltritert-butylperoxide, β-hydroxyethyl-γ-aminopropyltriethoxysiloxane, anilinemethyltriethoxysilane, and diethylenetriaminopropyltriethoxysilane.

[0072] The method for preparing the epoxy resin composition provided by this invention includes uniformly mixing epoxy resin, trifunctional epoxy compound, toughening agent, curing agent, and optionally colorant and coupling agent to obtain the epoxy resin composition. The mixing method is not particularly limited; the materials can be added and mixed uniformly in any order. For example, the epoxy resin, toughening agent, curing agent, and optionally colorant and coupling agent can be stirred and mixed in a container. The container walls are opened and scraped every 10-20 minutes of stirring, and then stirring continues. After the micelles are mixed, vacuum degassing is initiated while stirring is in operation. After vacuum degassing for 10-20 minutes, the material is discharged to obtain the epoxy resin composition.

[0073] The present invention also provides the application of the epoxy resin composition as a bottom filler adhesive for electronic products.

[0074] The present invention will be further described below with reference to the embodiments.

[0075] In the following examples and comparative examples, bisphenol F diglycidyl ether was purchased from Mitsubishi Chemical Corporation, grade 806, with an epoxy equivalent of 160 g / eq; bisphenol A diglycidyl ether was purchased from Mitsubishi Chemical Corporation, grade 828, with an epoxy equivalent of 184 g / eq; and SBS thermoelastic resin was purchased from Kraton, grade D1155.

[0076] Preparation Example 1-1: Preparation of Trifunctional Epoxides

[0077] S1. 9.2 g (0.1 mol, 1 eq) of epichlorohydrin was dissolved in 200 mL of acetonitrile, followed by the addition of 41.5 g (0.3 mol, 3.05 eq) of potassium carbonate and 3.2 g (0.01 mol, 0.1 eq) of tetrabutylammonium bromide. The mixture was heated to 60 °C and stirred for 20 min under inert gas protection. Then, 19.4 g (0.1 mol, 1 eq) of tetraethylene glycol was slowly added and the mixture was reacted for 12 h. The solvent was then recovered by vacuum distillation, followed by washing with water and drying to obtain 23 g of intermediate I. 23 g (91 mmol, 1 eq) of intermediate I was dissolved in 200 mL of dichloromethane. After nitrogen purging, 13.8 g (136.5 mmol, 1.5 eq) of triethylamine and 15 g (0.1 mol, 1 eq) of TBSCl were added. The mixture was stirred at 10 °C for 6 h. After the reaction was completed, the solvent was removed by vacuum distillation. The crude product was washed with water and dried to obtain 27 g of intermediate II.

[0078] S2. 15.1 g (0.1 mol, 1 eq) of 2,6-dicarboxaldehyde-4-hydroxypyridine was dissolved in 200 mL of tetrahydrofuran, cooled to 0 °C, and 6.4 g (0.1 mol, 1 eq) of n-butyllithium and 37.3 g (0.11 mol, 1.1 eq) of triphenylmethylphosphorus bromide were added under argon protection. The mixture was stirred for 1 h, and after the reaction was completed, it was quenched with water. The mixture was then extracted with 200 mL of dichloromethane, and the organic phase was distilled under reduced pressure to remove the solvent, yielding 12 g of 2,6-diethylene-4-hydroxypyridine. 12 g (80 mmol, 1 eq) of 2,6-diethylene-4-hydroxypyridine was dissolved in 160 mL of N,N-dimethylformamide, followed by the addition of 33.7 g (244 mmol, 3.05 eq) of potassium carbonate and 1 g (DMAP, 8 mmol, 0.1 eq) of 4-dimethylaminopyridine. After heating to 70 °C, 40 g (0.11 mol, 1.1 eq) of intermediate II was slowly added. After the addition was complete, the reaction was stirred for 8 h. After the reaction was completed, water was added to quench the reaction, and the solvent was removed by extraction and vacuum distillation to obtain 40.2 g of intermediate III. 40.2 g (84 mmol, 1 eq) of intermediate III was dissolved in 160 mL of dichloromethane, cooled to 0 °C, and 43.5 g (252 mmol, 3 eq) of m-CPBA was slowly added. The temperature was then raised to 40 °C, and the reaction was continued at this temperature for 12 h. The solution was then diluted with dichloromethane and washed three times with saturated sodium bicarbonate aqueous solution and two times with saturated sodium thiosulfate aqueous solution. The organic phase was collected and evaporated to dryness to obtain 36.9 g of trifunctional epoxy compound, denoted as EP-1.

[0079] The overall yield of the reaction was 72.1%. The NMR results are as follows: 1H NMR (400 MHz, DMSO-d6) δ 7.05(s, 2H), 4.16 (dt, J = 12.3, 6.1 Hz, 1H), 4.02 (dt, J = 12.4, 6.2 Hz, 1H), 3.94(t, J =5.1 Hz, 2H), 3.82 (dt, J = 12.4, 6.2 Hz, 1H), 3.77 -3.71 (m, 3H), 3.74-3.55 (m, 15H), 3.42 (dd, J = 7.2, 5.5 Hz, 1H), 2.97 (dd, J = 7.2, 5.5 Hz, 1H), 2.89 (p, J =5.6 Hz, 1H). The NMR results show that the trifunctional epoxy compound has the structure shown in formula (1).

[0080] Preparation Examples 1-2: Preparation of Trifunctional Epoxides

[0081] S1. 46 g (0.5 mol, 1 eq) of epichlorohydrin was dissolved in 1 L of acetonitrile, followed by the addition of 207.3 g (1.5 mol, 3.05 eq) of potassium carbonate and 16 g (0.05 mol, 0.1 eq) of tetrabutylammonium bromide. The mixture was heated to 50 °C and stirred for 20 min under inert gas protection. Then, 97 g (0.5 mol, 1 eq) of tetraethylene glycol was slowly added and the mixture was reacted for 24 h. The solvent was then recovered by vacuum distillation, followed by washing with water and drying to obtain 107 g of intermediate I. 107 g (0.42 mol, 1 eq) of intermediate I was dissolved in 1 L of dichloromethane. After nitrogen purging, 63.7 g (0.63 mol, 1.5 eq) of triethylamine and 63.3 g (0.42 mol, 1 eq) of TBSCl were added. The mixture was stirred at 30 °C for 5 h. After the reaction was completed, the solvent was removed by vacuum distillation. The crude product was washed with water and dried to obtain 119 g of intermediate II.

[0082] S2. 75.5 g (0.5 mol, 1 eq) of 2,6-dicarboxaldehyde-4-hydroxypyridine was dissolved in 1 L of tetrahydrofuran, cooled to -20 °C, and 32 g (0.5 mol, 1 eq) of n-butyllithium and 188.76 g (0.55 mol, 1.1 eq) of triphenylphosphine bromide were added under argon protection. The mixture was stirred for 24 h. After the reaction was completed, the mixture was quenched with water, extracted with 500 mL of dichloromethane, and the organic phase was then distilled under reduced pressure to remove the solvent, yielding 62 g of 2,6-diethylene-4-hydroxypyridine. 62 g (0.41 mol, 1 eq) of 2,6-diethylene-4-hydroxypyridine was dissolved in 800 mL of N,N-dimethylformamide, followed by the addition of 33.7 g (1.25 mol, 3.05 eq) of potassium carbonate and 4.9 g (40.1 mmol, 0.1 eq) of DMAP. The temperature was maintained at 25 °C, and then 112.8 g (0.45 mol, 1.1 eq) of intermediate II was slowly added. After the addition was complete, the reaction was stirred for 18 h. After the reaction was completed, water was added to quench the reaction, and the solvent was removed by extraction and vacuum distillation to obtain 204 g of intermediate III. 204 g (0.43 mol, 1 eq) of intermediate III was dissolved in 800 mL of dichloromethane, cooled to 0 °C, and 220.8 g (1.28 mol, 3 eq) of m-CPBA was slowly added. The temperature was raised to 60 °C, and the reaction was continued at this temperature for 18 h. Then, dichloromethane was added to dilute the solution, and the solution was washed three times with saturated sodium bicarbonate aqueous solution and then twice with saturated sodium thiosulfate aqueous solution. The organic phase was collected and evaporated to dryness to obtain 172 g of trifunctional epoxy compound, denoted as EP-2.

[0083] The overall yield of the reaction was 67.4%. The NMR results are as follows: 1 H NMR (400 MHz, DMSO-d6) δ 7.05(s, 2H), 4.16 (dt, J = 12.3, 6.1 Hz, 1H), 4.02 (dt, J = 12.4, 6.2 Hz, 1H), 3.94(t, J =5.1 Hz, 2H), 3.82 (dt, J = 12.4, 6.2 Hz, 1H), 3.77 -3.71 (m, 3H), 3.74-3.55 (m, 15H), 3.42 (dd, J = 7.2, 5.5 Hz, 1H), 2.97 (dd, J = 7.2, 5.5 Hz, 1H), 2.89 (p, J=5.6 Hz, 1H). The NMR results show that the trifunctional epoxy compound has the structure shown in formula (1).

[0084] Preparation Examples 1-3: Preparation of Trifunctional Epoxides

[0085] S1. 92 g (1 mol, 1 eq) of epichlorohydrin was dissolved in 2 L of acetonitrile, followed by the addition of 414.6 g (3 mol, 3.05 eq) of potassium carbonate and 32 g (0.1 mol, 0.1 eq) of tetrabutylammonium bromide. The mixture was heated to 70 °C and stirred for 20 min under inert gas protection. Then, 213 g (1.1 mol, 1.1 eq) of tetraethylene glycol was slowly added and the mixture was reacted for 10 h. The solvent was then recovered by vacuum distillation, washed with water, and dried to obtain 240 g of intermediate I. 240 g (0.6 mol, 1 eq) of intermediate I was dissolved in 1200 mL of dichloromethane. After nitrogen purging, 91 g (0.9 mol, 1.5 eq) of triethylamine and 90.4 g (0.6 mol, 1 eq) of TBSCl were added. The mixture was stirred at 20 °C for 12 h. After the reaction was complete, the solvent was removed by vacuum distillation. The crude product was washed with water and dried to obtain 290 g of intermediate II.

[0086] S2. 151.1 g (1 mol, 1 eq) of 2,6-dicarboxaldehyde-4-hydroxypyridine was dissolved in 2 L of tetrahydrofuran, cooled to -10 °C, and 64 g (1 mol, 1 eq) of n-butyllithium and 377.5 g (1.1 mol, 1.1 eq) of triphenylphosphine bromide were added under argon protection. The mixture was stirred for 10 h. After the reaction was completed, water was added to quench the reaction, followed by extraction with 800 mL of dichloromethane. The organic phase was then distilled under reduced pressure to remove the solvent, yielding 140 g of 2,6-diethylene-4-hydroxypyridine. 140 g (0.94 mol, 1 eq) of 2,6-diethylene-4-hydroxypyridine was dissolved in 1.6 L of N,N-dimethylformamide, followed by the addition of 1.3 kg (9.38 mol, 3.05 eq) of potassium carbonate and 10 g (80 mmol, 0.1 eq) of DMAP. After heating to 100 °C, 400 g (1.1 mol, 1.1 eq) of intermediate II was slowly added. After the addition was complete, the mixture was stirred for 2 h. After the reaction was completed, water was added to quench the reaction, and the solvent was removed by extraction and vacuum distillation to obtain 410 g of intermediate III. 410 g (0.86 mol, 1 eq) of intermediate III was dissolved in 1600 mL of dichloromethane, cooled to 0 °C, and 445 g (2.58 mol, 3 eq) of m-CPBA was slowly added. The temperature was raised to 100 °C, and the reaction was continued at this temperature for 6 h. Then, dichloromethane was added to dilute the solution, and the solution was washed three times with saturated sodium bicarbonate aqueous solution and then twice with saturated sodium thiosulfate. The organic phase was collected and evaporated to dryness to obtain 382 g of trifunctional epoxy compound, denoted as EP-1.

[0087] The overall yield of the reaction was 74.8%. The NMR results are as follows: 1 H NMR (400 MHz, DMSO-d6) δ 7.05(s, 2H), 4.16 (dt, J = 12.3, 6.1 Hz, 1H), 4.02 (dt, J = 12.4, 6.2 Hz, 1H), 3.94(t, J =5.1 Hz, 2H), 3.82 (dt, J = 12.4, 6.2 Hz, 1H), 3.77 -3.71 (m, 3H), 3.74-3.55 (m, 15H), 3.42 (dd, J = 7.2, 5.5 Hz, 1H), 2.97 (dd, J = 7.2, 5.5 Hz, 1H), 2.89 (p, J=5.6 Hz, 1H). The NMR results show that the trifunctional epoxy compound has the structure shown in formula (1).

[0088] Preparation Example 2-1: Preparation of Cyclic Anhydride Compounds

[0089] S1`. A polyhydroxy aromatic compound (having the structure shown in formula (II), R3, R4, R5, R 10 R 11 and R 12 All of the above (0.6 g, 3.0 mmol) were dissolved in methanol (30 mL), and KOH (1.0 g, 18 mmol) was added. The mixture was stirred until clear, and acrylonitrile (2.4 mL, 36 mmol) was added dropwise under ice bath conditions. The mixture was stirred at 20 °C for 24 h. After the reaction was completed, the reaction was quenched with water. The resulting product was then extracted three times with dichloromethane. The organic phase was washed successively with saturated NaCl solution, dried over anhydrous Na2SO4, the organic solvent was removed under reduced pressure, and purified by column chromatography to obtain a polycyano aromatic compound (white solid).

[0090] S2. Dissolve the polycyano aromatic compound (0.73 g, 1.5 mmol) in methanol (20 mL), add concentrated hydrochloric acid (5 mL), and reflux for 12 h. After the reaction is complete, remove the methanol by rotary evaporation, dissolve the residue in water, extract three times with dichloromethane, acidify the aqueous phase to pH 2 with concentrated hydrochloric acid, precipitate a white solid, filter, and dry to obtain the polycarboxylic aromatic compound.

[0091] S3. A polycarboxylated aromatic compound (0.34 g, 0.7 mmol) was dissolved in dichloromethane (20 mL), and DCC (0.3 g, 1.5 mmol) was added. The mixture was stirred at 25 °C for 24 h. After the reaction was complete, dicyclohexylurea was removed by filtration, and the filtrate was concentrated by rotary evaporation and purified by column chromatography to give 0.25 g of a cyclic anhydride compound (white solid, denoted as AH-1), with a yield of 80%.

[0092] The NMR data and characteristic data of this cyclic anhydride compound are as follows: 1 H NMR (400 MHz, DMSO-d6) δ7.20 (p, J = 1.0 Hz, 2H), 4.57 (d, J = 1.0 Hz, 8H), 3.75 (t, J = 7.1 Hz, 8H), 2.62(t, J = 7.1 Hz, 8H). From the above results, it can be seen that this cyclic anhydride compound has the structure shown in formula (1'), and R1, R2, R3, R4, R5, R6, R7, R8, R9, R... 10 R11 R 12 R 13 and R 14 All are H.

[0093] Preparation Example 2-2: Preparation of Cyclic Anhydride Compounds

[0094] S1`. A polyhydroxy aromatic compound (having the structure shown in formula (II), R3, R4, R5, R 10 R 11 and R 12 All of the above (0.6 g, 3.0 mmol) were dissolved in ethanol (30 mL), and NaOH (0.6 g, 15 mmol) was added. The mixture was stirred until clear, and acrylonitrile (1 mL, 15 mmol) was added dropwise under ice bath conditions. The mixture was stirred at 50 °C for 8 h. After the reaction was completed, the reaction was quenched with water. The resulting product was then extracted three times with dichloromethane. The organic phase was washed successively with saturated NaCl solution, dried over anhydrous Na2SO4, the organic solvent was removed under reduced pressure, and purified by column chromatography to obtain a polycyano aromatic compound (white solid).

[0095] S2. Dissolve the polycyano aromatic compound (0.73 g, 1.5 mmol) in methanol (15 mL), add concentrated hydrochloric acid (5 mL), and reflux for 24 h. After the reaction is complete, remove the methanol by rotary evaporation, dissolve the residue in water, extract three times with dichloromethane, acidify the aqueous phase to pH 2 with concentrated hydrochloric acid, precipitate a white solid, filter, and dry to obtain the polycarboxylic aromatic compound.

[0096] S3. A polycarboxylated aromatic compound (0.34 g, 0.7 mmol) was dissolved in dichloromethane (20 mL), and DCC (0.35 g, 1.75 mmol) was added. The mixture was stirred at 0 °C for 36 h. After the reaction was complete, dicyclohexylurea was removed by filtration, and the filtrate was concentrated by rotary evaporation and purified by column chromatography to give 0.24 g of a cyclic anhydride compound (white solid, denoted as AH-2), with a yield of 78%.

[0097] The NMR data and characteristic data of this cyclic anhydride compound are basically the same as those of Preparation Example 2-1. It can be seen that this cyclic anhydride compound has the structure shown in formula (1'), and R1, R2, R3, R4, R5, R6, R7, R8, R9, R... 10 R 11 R 12 R 13 and R 14 All are H.

[0098] Preparation Examples 2-3: Preparation of Cyclic Anhydride Compounds

[0099] S1`. A polyhydroxy aromatic compound (having the structure shown in formula (II), R3, R4, R5, R 10 R 11 and R 12 All of the above (0.6 g, 3.0 mmol) were dissolved in ethanol (30 mL), and K2CO3 (3.3 g, 24 mmol) was added. The mixture was stirred until clear, and acrylonitrile (2 mL, 30 mmol) was added dropwise under ice bath conditions. The mixture was stirred at 35 °C for 15 h. After the reaction was completed, the reaction was quenched with water. The resulting product was then extracted three times with dichloromethane. The organic phase was washed successively with saturated NaCl solution, dried over anhydrous Na2SO4, the organic solvent was removed under reduced pressure, and purified by column chromatography to obtain a polycyano aromatic compound (white solid).

[0100] S2. Dissolve 0.73 g (1.5 mmol) of a polycyano aromatic compound in methanol (25 mL), add concentrated hydrochloric acid (5 mL), and reflux for 6 h. After the reaction is complete, remove methanol by rotary evaporation, dissolve the residue in water, extract three times with dichloromethane, acidify the aqueous phase to pH 2 with concentrated hydrochloric acid, precipitate a white solid, filter, and dry to obtain the polycarboxylic aromatic compound.

[0101] S3. A polycarboxylated aromatic compound (0.34 g, 0.7 mmol) was dissolved in dichloromethane (20 mL), and DCC (0.42 g, 2.1 mmol) was added. The mixture was stirred at 30 °C for 10 h. After the reaction was complete, dicyclohexylurea was removed by filtration, and the filtrate was concentrated by rotary evaporation and purified by column chromatography to give 0.23 g of a cyclic anhydride compound (white solid, denoted as AH-3), with a yield of 75%.

[0102] The NMR data and characteristic data of this cyclic anhydride compound are basically the same as those of Preparation Example 2-1. It can be seen that this cyclic anhydride compound has the structure shown in formula (1'), and R1, R2, R3, R4, R5, R6, R7, R8, R9, R... 10 R 11 R 12 R 13 and R 14 All are H.

[0103] Example 1: Epoxy Resin Composition and its Preparation Method

[0104] (1) The raw material composition is as follows:

[0105] 25 parts by weight of bisphenol A diglycidyl ether;

[0106] 10 parts by weight of bisphenol F diglycidyl ether;

[0107] 19 parts by weight of trifunctional epoxy compound (EP-1);

[0108] 20 parts by weight of SBS thermoelastic resin;

[0109] 20 parts by weight of methylnadic anhydride;

[0110] 1 part by weight of carbon black;

[0111] 5 parts by weight of γ-epoxypropoxypropyltrimethoxysiloxane.

[0112] (2) Preparation method of epoxy resin composition:

[0113] Bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, trifunctional epoxy compound, SBS thermoelastic resin, methyl nadic anhydride, carbon black, and γ-epoxypropoxypropyltrimethoxysiloxane were stirred and mixed in a dual planetary hybrid stirring vessel for 30 minutes. The vessel walls were scraped every 10 minutes of stirring, and then stirring was continued. After the micelles were mixed, vacuum degassing was started while stirring was started. After vacuum degassing for 10 minutes, the material was discharged to obtain the epoxy resin composition.

[0114] Example 2: Epoxy Resin Composition and its Preparation Method

[0115] (1) The raw material composition is as follows:

[0116] 25 parts by weight of bisphenol A diglycidyl ether;

[0117] 25 parts by weight of bisphenol F diglycidyl ether;

[0118] 5 parts by weight of trifunctional epoxy compound (EP-2);

[0119] 10 parts by weight of SBS thermoelastic resin;

[0120] 30 parts by weight of methylnadic anhydride;

[0121] 1 part by weight of carbon black;

[0122] 4 parts by mass of γ-epoxypropoxypropyltrimethoxysiloxane.

[0123] (2) Preparation method of epoxy resin composition:

[0124] Bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, trifunctional epoxy compound, SBS thermoelastic resin, methyl nadic anhydride, carbon black, and γ-epoxypropoxypropyltrimethoxysiloxane were stirred and mixed in a dual planetary hybrid stirring vessel for 30 minutes. The vessel walls were scraped every 10 minutes of stirring, and then stirring was continued. After the micelles were mixed, vacuum degassing was started while stirring was started. After vacuum degassing for 10 minutes, the material was discharged to obtain the epoxy resin composition.

[0125] Example 3: Epoxy Resin Composition and its Preparation Method

[0126] (1) The raw material composition is as follows:

[0127] 4 parts by weight of bisphenol A diglycidyl ether;

[0128] 10 parts by weight of bisphenol F diglycidyl ether;

[0129] 30 parts by weight of trifunctional epoxy compound (EP-3);

[0130] 30 parts by weight of SBS thermoelastic resin;

[0131] 15 parts by weight of methylnadic anhydride;

[0132] 1 part by weight of carbon black;

[0133] 10 parts by weight of γ-epoxypropoxypropyltrimethoxysiloxane.

[0134] (2) Preparation method of epoxy resin composition:

[0135] Bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, trifunctional epoxy compound, SBS thermoelastic resin, methyl nadic anhydride, carbon black, and γ-epoxypropoxypropyltrimethoxysiloxane were stirred and mixed in a dual planetary hybrid stirring vessel for 30 minutes. The vessel walls were scraped every 10 minutes of stirring, and then stirring was continued. After the micelles were mixed, vacuum degassing was started while stirring was started. After vacuum degassing for 10 minutes, the material was discharged to obtain the epoxy resin composition.

[0136] Example 4: Epoxy Resin Composition and its Preparation Method

[0137] An epoxy resin composition was prepared according to the method of Example 1, except that the methyl nadic anhydride was replaced by the same amount of cyclic anhydride compound AH-1 obtained from Preparation Example 2-1, and the other conditions were the same as in Example 1, to obtain the epoxy resin composition.

[0138] Example 5: Epoxy Resin Composition and its Preparation Method

[0139] An epoxy resin composition was prepared according to the method of Example 1, except that methyl nadic anhydride was replaced by a mixture of the same weight parts of cyclic anhydride compound AH-2 obtained from Preparation Example 2-2 and bicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride in a mass ratio of 2:1, and the other conditions were the same as in Example 1, to obtain the epoxy resin composition.

[0140] Example 6: Epoxy Resin Composition and its Preparation Method

[0141] An epoxy resin composition was prepared according to the method of Example 1, except that methyl nadic anhydride was replaced by a mixture of the same weight parts of cyclic anhydride compound AH-3 obtained from Preparation Examples 2-3 and 2,2-dimethylsuccinic anhydride in a mass ratio of 4:1, and the other conditions were the same as in Example 1, to obtain the epoxy resin composition.

[0142] Comparative Example 1: Reference epoxy resin composition and its preparation method

[0143] An epoxy resin composition was prepared according to the method of Example 1, except that the trifunctional epoxy compound was replaced with the same amount of bisphenol A bisglycidyl ether by weight, and the other conditions were the same as in Example 1, to obtain a reference epoxy resin composition.

[0144] Comparative Example 2: Reference epoxy resin composition and its preparation method

[0145] An epoxy resin composition was prepared according to the method of Example 1, except that the trifunctional epoxy compound was replaced with the same amount of bisphenol F bisglycidyl ether by weight, and the other conditions were the same as in Example 1, to obtain a reference epoxy resin composition.

[0146] Test case

[0147] (1) Viscosity: The viscosity of the epoxy resin compositions obtained in the above examples and the reference epoxy resin compositions obtained in the comparative examples was tested using a BROOKFIELD viscometer immediately after preparation and after standing for 24 hours. The test conditions included: at room temperature, the viscosity data was measured after rotating a 29# rotor at 5 rpm for 30 minutes. The results are shown in Table 1.

[0148] (2) Elongation at break: The epoxy resin compositions obtained in the above examples and the reference epoxy resin composition obtained in the comparative example were cured and made into dog bone samples. The samples were heated to 245°C at room temperature and held at high temperature for 1 min on a DMA instrument in tensile mode, and then loaded to 18 N at 5 N / min. The results are shown in Table 1.

[0149] (3) Adhesive strength: The epoxy resin compositions obtained in the above embodiments and the reference epoxy resin composition obtained in the comparative example were coated on a silicon wafer, and then covered and pressed onto an FR5 substrate to make test samples. The bonding area was 2mm×2mm and the adhesive layer thickness was 50μm. The samples were cured at 150℃ for 120min. The cured samples were then pushed sideways using a Dage 4000 and tested under high temperature (260℃) conditions. The measured force values ​​were recorded as high temperature adhesive strength (MPa). After curing, the samples were treated under heating and humidification conditions of 85℃ / 85%RH for 120h, and then the adhesive strength was tested again under high temperature (260℃) conditions. The measured force values ​​were recorded as aging high temperature adhesive strength (MPa). The results are shown in Table 1.

[0150] Table 1

[0151]

[0152] As can be seen from the results in Table 1, the epoxy resin compositions provided in Examples 1-6, with the addition of a trifunctional epoxy compound with the structure shown in Formula (1), showed that the elongation at break could reach more than 2.2%. The only difference between Comparative Examples 1 and 2 and Example 1 was the absence of a trifunctional epoxy compound with the structure shown in Formula (1), resulting in elongations at break reduced to 1.5% and 1.8%, respectively. This demonstrates that the trifunctional epoxy compound with the structure shown in Formula (1) can impart good toughness to the epoxy resin composition. A comparison between Example 1 and Example 4 shows that when the curing agent contains a cyclic anhydride compound with the structure shown in Formula (1'), it can impart higher high-temperature adhesive strength to the epoxy resin composition without significantly affecting its toughness.

[0153] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. An epoxy resin composition, characterized in that, The epoxy resin composition contains an epoxy resin, a trifunctional epoxy compound, a toughening agent, a curing agent, and optionally a colorant and a coupling agent; the mass ratio of the epoxy resin to the trifunctional epoxy compound is 100:(10-300); the trifunctional epoxy compound has the structure shown in formula (1): Equation (1), In equation (1), R 1 and R 2 Each is independently an H or C1-C5 alkyl group.

2. The epoxy resin composition according to claim 1, characterized in that, The epoxy resin content is 10-50 parts by weight, the trifunctional epoxy compound content is 5-30 parts by weight, the toughening agent content is 10-30 parts by weight, the curing agent content is 10-50 parts by weight, the colorant content is 0.5-2 parts by weight, and the coupling agent content is 1-10 parts by weight.

3. The epoxy resin composition according to claim 1, characterized in that, The trifunctional epoxy compound was prepared by a method comprising the following steps: S1. The halo-oxidized propylene oxide shown in formula (2) and the triethylene glycol shown in formula (3) are subjected to a first substitution reaction in the presence of base I and catalyst I at a molar ratio of 1:(1-1.1). The resulting intermediate I is subjected to an active group protection reaction in the presence of base II to obtain intermediate II. S2. The 2,6-dicarboxaldehyde-4-hydroxypyridine shown in formula (4) is subjected to a Wittig reaction with phosphorus ylide. The resulting vinyl hydroxypyridine is subjected to a second substitution reaction with intermediate II in the presence of base III and catalyst II. Then, the resulting intermediate III is subjected to an oxidation reaction to obtain a product containing a trifunctional epoxy compound. Equation (2), Equation (3), Equation (4), In equation (2), X is a halogen; In equation (4), R 1 and R 2 Each is independently an H or C1-C5 alkyl group.

4. The epoxy resin composition according to claim 3, characterized in that, In step S1, the method for the first substitution reaction and the active group protection reaction includes dissolving halopropylene oxide, base I, and catalyst I in organic solvent I, heating the resulting mixture to the first substitution reaction temperature under inert gas protection and stirring, then adding tetraethylene glycol trioxide to carry out the first substitution reaction, removing the solvent after the reaction is complete, washing the crude product with water and drying it, then dissolving the obtained intermediate I, base II, and active group protectant in organic solvent II to carry out the active group protection reaction, removing the solvent after the reaction is complete, washing the crude product with water and drying it to obtain intermediate II.

5. The epoxy resin composition according to claim 4, characterized in that, The conditions for the first substitution reaction include a temperature of 50℃-70℃ and a time of 10h-24h.

6. The epoxy resin composition according to claim 4, characterized in that, The conditions for the active group protection reaction include a temperature of 10℃-30℃ and a time of 5h-12h.

7. The epoxy resin composition according to claim 4, characterized in that, In step S2, the Wittig reaction, the second substitution reaction, and the oxidation reaction are performed by dissolving 2,6-dicarboxaldehyde-4-hydroxypyridine and phosphorus ylide in organic solvent III, and then reacting at the Wittig reaction temperature under inert gas protection. After the reaction is completed, water is added to quench the reaction, followed by extraction, solvent removal, and drying to obtain vinyl hydroxypyridine. Vinyl hydroxypyridine, base III, and catalyst II are dissolved in organic solvent IV, and the temperature is raised to the second substitution reaction temperature under inert gas protection and stirring. Then, intermediate II is added to carry out the second substitution reaction. After the reaction is completed, the solvent is removed to obtain intermediate III. Intermediate III is dissolved in organic solvent V, cooled to -5℃ to 5℃, and then an oxidant is slowly added. The temperature is then raised to the oxidation reaction temperature to continue the reaction. After the reaction is completed, a product containing a trifunctional epoxy compound is obtained.

8. The epoxy resin composition according to claim 7, characterized in that, The phosphorus ylide is generated by triphenylmethylphosphorus bromide under the action of a strong base.

9. The epoxy resin composition according to claim 8, characterized in that, The strong base is selected from at least one of n-butyllithium, phenyllithium, potassium tert-butoxide, and sodium tert-butoxide.

10. The epoxy resin composition according to claim 7, characterized in that, The conditions for the Wittig reaction include a temperature of -20℃ to 0℃ and a time of 1h to 24h.

11. The epoxy resin composition according to claim 7, characterized in that, The conditions for the second substitution reaction include a temperature of 25℃-100℃ and a time of 2h-18h.

12. The epoxy resin composition according to claim 7, characterized in that, The oxidation reaction conditions include a temperature of 40℃-100℃ and a time of 6h-18h.

13. The epoxy resin composition according to claim 3, characterized in that, The method for preparing the trifunctional epoxy compound further includes purifying and separating the trifunctional epoxy compound from the product containing the trifunctional epoxy compound. The purification method includes adding organic solvent VI to the product containing the trifunctional epoxy compound for dilution, then washing the resulting diluted solution sequentially with saturated sodium bicarbonate aqueous solution and saturated sodium thiosulfate aqueous solution, collecting the organic phase and removing the solvent to obtain the trifunctional epoxy compound.

14. The epoxy resin composition according to any one of claims 1-13, characterized in that, The curing agent contains at least a cyclic anhydride compound having the structure shown in formula (1'); Equation (1'), In equation (1), R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 R 13 and R 14 Each is an alkyl group that is independently H or C1 to C6.

15. The epoxy resin composition according to claim 14, characterized in that, The cyclic anhydride compounds account for 10-100% of the total weight of the curing agent.

16. The epoxy resin composition according to claim 14, characterized in that, The cyclic anhydride compounds have a symmetrical structure.

17. The epoxy resin composition according to any one of claims 1-13, characterized in that, The epoxy resin is selected from at least one of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, o-hydroxymethyl bisphenol A diglycidyl ether, dihydroxymethyl bisphenol A diglycidyl ether, tetrabromobisphenol A diglycidyl ether, resorcinol diglycidyl ether, and pyrogallol triglycidyl ether pentaerythritol diglycidyl ether.

18. The epoxy resin composition according to claim 17, characterized in that, The epoxy resin is bisphenol A bisglycidyl ether and / or bisphenol F bisglycidyl ether.

19. The epoxy resin composition according to any one of claims 1-13, characterized in that, The toughening agent is selected from at least one of polyurethane, cashew nut shell liquid modified phenolic resin, unsaturated polyester resin, epoxy resin active toughening agent and SBS thermoplastic elastomer.

20. The epoxy resin composition according to any one of claims 1-13, characterized in that, The coupling agent is selected from at least one of γ-aminopropyltriethylsiloxane, γ-epoxypropoxypropyltrimethoxysiloxane, γ-methacrylate propyltrimethoxysiloxane, γ-thiol propyltrimethoxysiloxane, vinyltritert-butylperoxide, β-hydroxyethyl-γ-aminopropyltriethoxysiloxane, anilinemethyltriethoxysilane, and diethylenetriaminopropyltriethoxysilane.

21. A method for preparing the epoxy resin composition according to any one of claims 1-20, characterized in that, The method involves uniformly mixing epoxy resin, trifunctional epoxy compound, toughening agent and curing agent, as well as optional colorant and coupling agent, to obtain an epoxy resin composition.

22. The use of the epoxy resin composition according to any one of claims 1-20 as a bottom filler adhesive for electronic products.

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