A cyclic anhydride compound, a preparation method and application thereof

Abstract

The application belongs to the field of organic synthesis, and particularly relates to a cyclic anhydride compound and a preparation method and application thereof. The cyclic anhydride compound has a structure shown in formula (1'). The preparation method of the cyclic anhydride compound provided by the application is started from a polyhydroxy aromatic compound, and the cyclic anhydride compound can be constructed through three steps of Michael addition, cyano hydrolysis and intramolecular condensation, without complex protection group operation, and the reaction temperature is below 70 DEG C, high temperature and high pressure are avoided, and the method is suitable for industrial scale production, and the yield of the target product is stable at 60% to 80%. In addition, when the cyclic anhydride compound is used as a curing agent of an epoxy resin composition, the epoxy resin composition can have high high-temperature-resistant bonding strength and high Tg, and can meet the demand of the bottom filling adhesive in the field of semiconductor packaging. Formula (1')

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis, specifically relating to a cyclic acid anhydride compound, its preparation method, and its application. Background Technology

[0002] Cyclic acid anhydrides are important organic chemical intermediates. They can undergo ring-opening polymerization with epoxy compounds to produce polyesters, which can be widely used in adhesives, biodegradable materials, drug carriers, coatings and other fields.

[0003] However, existing synthetic techniques for cyclic anhydrides have significant limitations: (1) Protecting group-dependent strategies: stepwise protection and deprotection of active groups such as hydroxyl groups are required, resulting in 3-5 additional reaction steps; (2) Harsh reaction conditions: some methods rely on highly corrosive reagents such as concentrated sulfuric acid and trifluoroacetic acid, or require high-temperature and high-pressure reactors above 150°C, which not only increases equipment costs but also easily triggers side reactions, resulting in low purity of the target product; (3) Narrow substrate applicability: traditional methods are mostly applicable to the synthesis of simple chain anhydrides, and the construction efficiency of symmetrical cyclic structures is low, with generally low yields. Therefore, developing a synthetic method for cyclic anhydrides that is simple in steps, mild in conditions, and has stable yields has important practical value.

[0004] Underfill adhesives are resin adhesives used in electronic packaging processes. They penetrate micron-level gaps through capillary action and are primarily used in semiconductor packaging. Besides filling the gaps between common PCBs and chips, they are also used between flexible printed circuit boards (FPCBs) and chips. Compared to adhesives used between chips and PCBs, those used between chips and FPCBs present greater challenges in formulation design. In addition to possessing the basic properties of conventional underfill adhesives, these adhesives also need to exhibit stronger bonding strength and toughness.

[0005] Common curing agents include amine curing agents and acid anhydride curing agents. However, epoxy underfills using existing acid anhydride compounds as curing agents only achieve a bond strength of 11 MPa after aging at 85°C and 85% humidity for 120 hours, indicating low high-temperature bond strength. Furthermore, to ensure the operational stability of electronic products, the glass transition temperature (Tg) of the epoxy underfill must be higher than its operating temperature. If the operating temperature approaches or exceeds Tg, the epoxy underfill will soften rapidly due to increased molecular chain movement, leading to a decrease in strength and affecting the performance of the electronic products. Summary of the Invention

[0006] The first objective of this invention is to provide a cyclic anhydride compound that, when used as a curing agent for epoxy adhesives, can improve the high-temperature bonding strength and Tg of the epoxy adhesives.

[0007] A second objective of this invention is to provide a method for preparing the above-mentioned cyclic anhydride compounds.

[0008] A third objective of the present invention is to provide the application of the above-mentioned cyclic anhydride compounds in adhesives.

[0009] The cyclic anhydride compounds provided by this invention have the structure shown in formula (1'):

[0010] Equation (1'),

[0011] 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 independently an H or C1~C6 alkyl group.

[0012] The method for preparing cyclic anhydride compounds provided by this invention includes the following steps:

[0013] S1`. Michael addition: The polyhydroxy aromatic compound shown in formula (2`) is reacted with acrylonitrile by cyanoethylation to obtain a polycyano aromatic compound;

[0014] S2'. Cyano hydrolysis: The polycyano aromatic compound is hydrolyzed to convert the cyano group into a carboxyl group, yielding a polycarboxyl aromatic compound;

[0015] S3'. Intramolecular condensation: Intramolecular anhydride reaction of polycarboxylic aromatic compounds to obtain cyclic anhydride compounds;

[0016] Equation (2'),

[0017] In equation (2'), R3, R4, R5, R 10 R 11 and R 12 Each is an alkyl group that is independently H or C1 to C6.

[0018] The method for preparing cyclic anhydride compounds provided by this invention starts from polyhydroxy aromatic compounds and constructs cyclic anhydride compounds through a three-step reaction of Michael addition, cyano hydrolysis, and intramolecular condensation. It does not require complex protecting group operations, and the reaction temperature is carried out below 70°C, avoiding high temperature and high pressure, which is suitable for industrial scale-up production. At the same time, the yield of the target product is stable at 60%~80%. It has the advantages of simple steps, mild conditions and stable yield, and is suitable for industrial production.

[0019] Furthermore, the cyclic anhydride compounds provided by this invention possess a multifunctional anhydride structure and an aromatic ring structure, with the anhydride structure linked to the aromatic ring structure via ether bonds. The presence of the multifunctional anhydride structure enables the epoxy resin composition to form a cross-linked network structure, while the presence of the rigid aromatic ring structure enhances the stability of the formed network molecular structure. The covalent bonds forming the aromatic ring structure require higher temperatures to be broken, and the connection between the anhydride structure and the aromatic ring structure via ether bonds creates strong intermolecular forces between the two. These strong intermolecular forces prevent the molecular chains from undergoing thermal motion and deformation under high-temperature conditions, avoiding excessive relaxation and separation of the molecular chains. When used as a curing agent for epoxy resin compounds, this allows the epoxy resin composition to resist higher temperatures, resulting in higher high-temperature adhesive strength and Tg. Detailed Implementation

[0020] The cyclic anhydride compounds provided by this invention have the structure shown in formula (1'):

[0021] Equation (1'),

[0022] 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.

[0023] In this invention, 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 it is not easy for external conditions (such as temperature changes) to cause structural changes, resulting in higher high-temperature adhesive strength and Tg. 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.

[0024] The cyclic anhydride compounds provided by this invention are prepared by a method comprising the following steps:

[0025] S1'. Michael addition: A polyhydroxy aromatic compound is reacted with acrylonitrile via cyanoethylation to yield a polycyano aromatic compound;

[0026] S2'. Cyano hydrolysis: The polycyano aromatic compound is hydrolyzed to convert the cyano group into a carboxyl group, yielding a polycarboxyl aromatic compound;

[0027] S3`. Intramolecular condensation: Intramolecular anhydride reaction of polycarboxylic aromatic compounds to obtain cyclic anhydride compounds.

[0028] In the preparation of the above-mentioned cyclic anhydride compounds, the polyhydroxy aromatic compounds have the structure shown in formula (2'):

[0029] Equation (2'),

[0030] In equation (2'), R3, R4, R5, R 10 R 11 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.

[0031] 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.

[0032] In a preferred embodiment, in formula (2'), R3, R4, R5, R 10 R 11 and R 12 All are H.

[0033] 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.

[0034] 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 6 h to 24 h, such as 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, 22 h, 24 h, or any value between them.

[0035] 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.

[0036] The reaction mechanism for the preparation of the above-mentioned cyclic anhydride compounds is as follows:

[0037] .

[0038] The present invention also provides the application of the cyclic anhydride compounds in adhesives. Specifically, the epoxy resin composition provided by the present invention contains an epoxy resin, a toughening agent, a curing agent, and optionally a colorant and a coupling agent, wherein the curing agent contains at least a cyclic anhydride compound having the structure shown in formula (1'). Preferably, the mass ratio of the epoxy resin, toughening agent, curing agent, colorant, and coupling agent is 100:(20-300):(20-500):(0-20):(0-100). Specifically, the mass ratio of the epoxy resin to the toughening agent is preferably 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.

[0039] In a preferred embodiment, the epoxy resin content is 10-50 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. This combination allows for better synergistic effects, which is more conducive to improving high-temperature bonding strength and Tg. Specifically, the epoxy resin content can be 10, 15, 20, 25, 30, 35, 40, 45, 50 parts by weight or any value between them. The toughening agent content can be 10, 12, 15, 18, 20, 22, 25, 28, 30 parts by weight or any value between them. The curing agent content can be 10, 15, 20, 25, 30, 35, 40, 45, 50 parts by weight or any value between them. The content of the pigment can be 0.5, 0.8, 1, 1.2, 1.5, 1.8, or 2 parts by weight, or any value between them. The content of the coupling agent can be 1, 2, 4, 6, 8, or 10 parts by weight, or any value between them.

[0040] In the epoxy resin composition, the curing agent contains at least a cyclic anhydride compound, which 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 constitutes 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.

[0041] In the epoxy resin composition, the epoxy resin composition preferably further contains a trifunctional epoxy compound having the structure shown in formula (1). In this case, the epoxy resin composition can be endowed with good toughness without affecting its high-temperature adhesive strength and high Tg. In addition, the mass ratio of the trifunctional epoxy compound to the epoxy resin is preferably (10-300):100, such as 10:100, 20:100, 50:100, 80:100, 100:100, 120:100, 150:100, 180:100, 200:100, 220:100, 250:100, 280:100, 300:100 or any value between them.

[0042] Equation (1),

[0043] 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.

[0044] The present invention will be described in detail below through embodiments. These embodiments are intended to explain the invention and should not be construed as limiting it. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0045] 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.

[0046] Example 1: Preparation of cyclic acid anhydride compounds

[0047] S1`. A polyhydroxy aromatic compound (having the structure shown in formula (II), R3, R4, R5, R 10 R 11 and R 12All 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).

[0048] 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.

[0049] 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%.

[0050] 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 R 11 R 12 R 13 and R 14 All are H.

[0051] Example 2 Preparation of cyclic acid anhydride compounds

[0052] S1`. A polyhydroxy aromatic compound (having the structure shown in formula (II), R3, R4, R5, R 10 R 11 and R12 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).

[0053] 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.

[0054] 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%.

[0055] The NMR data and characteristic data of this cyclic anhydride compound are basically the same as those of Example 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.

[0056] Example 3 Preparation of cyclic acid anhydride compounds

[0057] S1`. A polyhydroxy aromatic compound (having the structure shown in formula (II), R3, R4, R5, R 10 R 11 and R 12All 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).

[0058] 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.

[0059] 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%.

[0060] The NMR data and characteristic data of this cyclic anhydride compound are basically the same as those of Example 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.

[0061] Example 4 Preparation of trifunctional epoxy compounds

[0062] 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.

[0063] 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.

[0064] 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).

[0065] Test Example 1

[0066] 19 parts by weight of bisphenol A diglycidyl ether, 25 parts by weight of bisphenol F diglycidyl ether, 20 parts by weight of SBS thermoelastic resin, 30 parts by weight of cyclic anhydride compound (AH-1), 1 part by weight of carbon black, and 5 parts by weight of γ-epoxypropoxypropyltrimethoxysiloxane were stirred and mixed in a dual planetary hybrid stirring vessel for 30 minutes. The vessel walls were scraped every 15 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.

[0067] (1) Tg (glass transition temperature): The epoxy resin composition was cured at 150℃ for 120 min, and then the Tg was determined using a differential calorimeter at a heating rate of 10℃ / min. The results are shown in Table 1.

[0068] (2) Adhesive strength: The epoxy resin composition was coated on a silicon wafer and then pressed onto an FR5 substrate to make a test sample. The bonding area was 2mm × 2.5mm and the adhesive layer thickness was 45μm. The sample was cured at 150℃ for 120min. The cured sample was then pushed sideways using a Dage 4000 and tested at a high temperature (260℃). The measured force value was recorded as the high-temperature adhesive strength (MPa). After curing, the sample was treated with heating and humidification conditions of 85℃ / 85%RH for 120h, and then the adhesive strength was tested at a high temperature (255℃). The measured force value was recorded as the aging high-temperature adhesive strength (MPa). The results are shown in Table 1.

[0069] (3) Modulus: After curing the epoxy resin composition at 160℃ / 100min, a sample with dimensions of 55mm×5mm×2mm was prepared and tested on a DMA. The measurement mode was dual cantilever mode, the vibration frequency was 1Hz, the amplitude was 10μm, the heating rate was 10°C / min, and the temperature range was -65℃~300℃. The modulus data at 200℃ were selected for comparison. The results are shown in Table 1.

[0070] (4) Elongation at break: After curing the epoxy resin composition, dog bone samples were made and stretched on a DMA instrument in tensile mode. The temperature was heated to 250°C at room temperature and held for 1.2 min. The sample was then loaded with 6 N / min up to 18 N. The results are shown in Table 1.

[0071] Test Example 2

[0072] 19 parts by weight of bisphenol A diglycidyl ether, 25 parts by weight of bisphenol F diglycidyl ether, 20 parts by weight of SBS thermoelastic resin, 15 parts by weight of cyclic anhydride compound (AH-2), 15 parts by weight of methyl nadic anhydride, 1 part by weight of carbon black, and 5 parts by weight of γ-epoxypropoxypropyltrimethoxysiloxane were stirred and mixed in a dual planetary hybrid stirring vessel for 30 minutes. The vessel walls were scraped every 15 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.

[0073] The Tg, bond strength, modulus and elongation at break of the epoxy resin composition were tested according to the method of Test Example 1, and the results are shown in Table 1.

[0074] Test Example 3

[0075] 19 parts by weight of bisphenol A diglycidyl ether, 25 parts by weight of bisphenol F diglycidyl ether, 20 parts by weight of SBS thermoelastic resin, 5 parts by weight of cyclic anhydride compound (AH-3), 25 parts by weight of methyl nadic anhydride, 1 part by weight of carbon black, and 5 parts by weight of γ-epoxypropoxypropyltrimethoxysiloxane were stirred and mixed in a dual planetary hybrid stirring vessel for 30 min. The vessel walls were scraped every 15 min 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 min, the material was discharged to obtain the epoxy resin composition.

[0076] The Tg, bond strength, modulus and elongation at break of the epoxy resin composition were tested according to the method of Test Example 1, and the results are shown in Table 1.

[0077] Test Example 4

[0078] An epoxy resin composition was prepared according to the method of Test Example 1, except that 30 parts by mass of the cyclic anhydride compound (AH-1) was replaced by a mixture of 25 parts by mass of the cyclic anhydride compound (AH-1) and 5 parts by mass of methylnadic anhydride, while the other conditions were the same as in Test Example 1, to obtain the epoxy resin composition.

[0079] The Tg, bond strength, modulus and elongation at break of the epoxy resin composition were tested according to the method of Test Example 1, and the results are shown in Table 1.

[0080] Test Example 5

[0081] An epoxy resin composition was prepared according to the method of Test Example 1, except that 19 parts by weight of bisphenol A diglycidyl ether was replaced by a mixture of 10 parts by weight of bisphenol A diglycidyl ether and 9 parts by weight of trifunctional epoxy compound (EP-1), and the remaining conditions were the same as in Test Example 1, to obtain the epoxy resin composition.

[0082] The Tg, bond strength, modulus and elongation at break of the epoxy resin composition were tested according to the method of Test Example 1, and the results are shown in Table 1.

[0083] Comparative Test Example 1

[0084] An epoxy resin composition was prepared according to the method of Test Example 2, except that the cyclic anhydride compound (AH-2) was replaced with the same amount of methyl nadic anhydride, and the other conditions were the same as in Test Example 2, to obtain a reference epoxy resin composition.

[0085] The Tg, bond strength, modulus and elongation at break of the reference epoxy resin composition were tested according to the method of Test Example 1, and the results are shown in Table 1.

[0086] Table 1

[0087]

[0088] As can be seen from the results of the examples, the total yield of cyclic anhydride compounds prepared by the method provided by the present invention can be consistently above 75%, and the efficient synthesis of cyclic anhydride compounds can be achieved.

[0089] As can be seen from the results in Table 1, the epoxy resin compositions provided in Test Examples 1-5 contain cyclic anhydride compounds with the structure shown in Formula (1). The results show that the high-temperature adhesive strength of the obtained epoxy resin compositions can reach above 20.88 MPa, the high-temperature adhesive strength after aging can reach above 12.95 MPa, and the Tg can reach above 118°C. That is, it has high high-temperature adhesive strength and high Tg, which can meet the requirements of bottom filler in the semiconductor packaging field. Compared with Test Example 2, the only difference between Test Example 1 and Test Example 2 is that the cyclic anhydride compound is replaced by the same weight of methyl nadic anhydride. The results show that the high-temperature adhesive strength of Test Example 1 is reduced to 15.23 MPa, the high-temperature adhesive strength after aging is reduced to 10.44 MPa, and the Tg is reduced to 109°C. The comparison between Test Example 1 and Test Example 5 shows that when the epoxy resin composition also contains a trifunctional epoxy compound with the structure shown in Formula (1), it can give the epoxy resin composition better toughness.

[0090] 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. A cyclic anhydride compound, characterized in that, The cyclic anhydride compounds have 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.

2. The cyclic anhydride compound according to claim 1, characterized in that, The cyclic anhydride compounds have a symmetrical structure.

3. The cyclic anhydride compound according to claim 1, characterized in that, In equation (1), R1, R2, R3, R4, R5, R6, R7, R8, R9, R 10 R 11 R 12 R 13 and R 14 All are H.

4. A method for preparing the cyclic anhydride compound according to any one of claims 1 to 3, characterized in that, The method includes the following steps: S1`. Michael addition: The polyhydroxy aromatic compound shown in formula (2`) is reacted with acrylonitrile by cyanoethylation to obtain a polycyano aromatic compound; S2'. Cyano hydrolysis: The polycyano aromatic compound is hydrolyzed to convert the cyano group into a carboxyl group, yielding a polycarboxyl aromatic compound; S3'. Intramolecular condensation: Intramolecular anhydride reaction of polycarboxylic aromatic compounds to obtain cyclic anhydride compounds; Equation (2'), In equation (2'), R3, R4, R5, R 10 R 11 and R 12 Each is an alkyl group that is independently H or C1 to C6.

5. The method for preparing cyclic anhydride compounds according to claim 4, characterized in that, The polyhydroxy aromatic compound has a symmetrical structure.

6. The method for preparing the cyclic anhydride compound according to claim 4, characterized in that, In equation (2), R3, R4, R5, R 10 R 11 and R 12 All are H.

7. The method for preparing cyclic anhydride compounds according to any one of claims 4 to 6, characterized in that, In step S1', the cyanoethylation reaction is carried out in the presence of an alkali and an organic solvent.

8. The method for preparing cyclic anhydride compounds according to claim 7, characterized in that, The molar ratio of the base to the polyhydroxy aromatic compound is 5:1 to 12:

1.

9. The method for preparing cyclic anhydride compounds according to any one of claims 4 to 6, characterized in that, In step S1', the amount of acrylonitrile used is 5 to 12 times the molar amount of the polyhydroxy aromatic compound.

10. The method for preparing cyclic anhydride compounds according to any one of claims 4 to 6, characterized in that, In step S1', the conditions for the cyanoethylation reaction include a temperature of 20~50℃ and a time of 8~24h.

11. The method for preparing cyclic anhydride compounds according to claim 7, characterized in that, The alkali is selected from at least one of potassium hydroxide, sodium hydroxide, potassium carbonate, and sodium carbonate.

12. The method for preparing cyclic anhydride compounds according to claim 7, characterized in that, The organic solvent is methanol and / or ethanol.

13. The method for preparing cyclic anhydride compounds according to any one of claims 4 to 6, characterized in that, In step S2', the hydrolysis reaction is carried out by reflux reaction of the polycyano aromatic compound in a concentrated hydrochloric acid / methanol system.

14. The method for preparing cyclic anhydride compounds according to claim 13, characterized in that, The volume ratio of concentrated hydrochloric acid to methanol is 1:3 to 1:

5.

15. The method for preparing cyclic anhydride compounds according to claim 13, characterized in that, The reflux reaction time is 6h~24h.

16. The method for preparing cyclic anhydride compounds according to any one of claims 4 to 6, characterized in that, In step S3', the intramolecular anhydride reaction is carried out in the presence of dicyclohexylcarbodiimide.

17. The method for preparing cyclic anhydride compounds according to claim 16, characterized in that, The molar ratio of the dicyclohexylcarbodiimide to the polycarboxylic aromatic compound is 2:1 to 3:

1.

18. The method for preparing cyclic anhydride compounds according to any one of claims 4 to 6, characterized in that, In step S3', the conditions for the intramolecular anhydride reaction include a temperature of 0~30℃ and a time of 10~36h.

19. The use of the cyclic anhydride compound according to any one of claims 1 to 3 in adhesives.

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